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Friday, December 27, 2019
USDA Approves First State and Tribal Hemp Production Plans
The U.S. Department of Agriculture (USDA) today
announced the first set of approved plans submitted by states and Indian tribes
for the domestic production of hemp under the U.S. Domestic Hemp Production
Program. The plans were submitted by the states of Louisiana, New Jersey, and
Ohio, and the Flandreau Santee Sioux, Santa Rosa Cahuilla, and La Jolla Band of
Luiseno Indian Tribes.
USDA continues to receive and review plans from
states and Indian tribes and maintains a list of all on our website, along
with approved plans. To check the status of a plan or to review approved plans,
visit: Status of State and Tribal Hemp Production Plans.
For additional information about the program and
the provisions of the interim final rule, visit the U.S. Domestic Hemp Production Program web page.
For information or questions related to a
specific plan, please contact the applicable state or tribe.
Thursday, December 26, 2019
Desert Horticulture Podcasts Make Top 15
Hi
Robert,
My name is Anuj Agarwal, I'm the Founder of Feedspot.
I would like to personally congratulate you as your website Desert Horticulture has been selected by our panelist as one of the Top 15 Horticulture Podcasts on the web.
https://blog.feedspot.com/horticulture_podcasts/
I personally give you a high-five and want to thank you for your contribution to this world. This is the most comprehensive list of Top 15 Horticulture Podcasts on the internet and I'm honored to have you as part of this!
My name is Anuj Agarwal, I'm the Founder of Feedspot.
I would like to personally congratulate you as your website Desert Horticulture has been selected by our panelist as one of the Top 15 Horticulture Podcasts on the web.
https://blog.feedspot.com/horticulture_podcasts/
I personally give you a high-five and want to thank you for your contribution to this world. This is the most comprehensive list of Top 15 Horticulture Podcasts on the internet and I'm honored to have you as part of this!
Anuj
Agarwal
Founder,
Feedspot
Email : aagarwal@feedspot.com
Monday, December 16, 2019
Controlling Springtails without Chemicals
Q. Each year around the end of February until the end of May
I experience and irritating problem with springtails. Do you have and
suggestions how to eliminate them? I don’t have decaying plants or problem with
water in that area.
A. Springtails are tiny insects that jump in the air en
masse when disturbed, usually at ground level. They love it wet.
Springtails are sometimes confused with leafhoppers. But leafhoppers, also very
small, reproduce and feed higher on plant leaves of plants like grapes and
vegetables. Leafhoppers start appearing about April or May, the time when
springtails are disappearing because of the heat and dryness. Both jump about
the same distances when disturbed but look totally different with a hand lens
or microscope.
I can
see you know this insect because springtails are found commonly in wet soils with
rotting or decaying plants or infesting open bodies of water like summing pools
and puddles. That would’ve been my first comment to you if you hadn’t made that
last statement. Sometimes springtails become a nuisance inside the house in wet
areas with light like bathrooms. Outside, I commonly see them in cooler, dark areas
of lawns that are kept too wet during the cooler months. Springtails like stagnant,
wet areas and are attracted to light. I’ve seen them as nuisance problems in
swimming pools or spas. Leafhoppers, on the other hand, like it hot and dry.
The
bottom line in all habitats suitable for springtails is water or wetness. If it’s
dry, they will disappear. They must feed and so rotting or decaying plants is
important nearby, but water and wetness is more important. So, in our
climate oftentimes they are found in irrigated shady spots.
I know
what you told me, but the key to managing or eliminating these guys is drying
up wet areas. This might be as simple as improving air circulation in that
area. Wetness is oftentimes accentuated in darker areas without much air
movement or north sides of buildings.
Pesticides
do not work in the long haul. It’s really getting the area to dry up will or at
least should clean up the problem. Ways to dry it out are to get more air
movement in that area and/or more light. The rooting plants (organic matter
they use for feed) will eventually disappear with time.
Be careful of excessive irrigation nearby. Do not water
daily. Water and then let the surface area dry out.
Use deeper rooted plants in the area if plants are there.
Bigger, deep rooted plants can handle longer periods of time without water
applied.
If mulch is present, let it dry out before irrigating
again or remove it. If rock is used, smaller rock like ¼ inch minus might allow
you to keep the area drier and longer times between irrigations.
If it is unbearable then try spraying the area starting
in late January with one of the horticultural oils. Spray the surface of the
soil in hopes of suffocating them.
I would like you to read the information at this link
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74136.html
Figs Need Water to Produce Figs
Q. We're considering planting a fig tree grove in our school
garden this year. How long typically does it take for them to produce figs ready
for harvest?
12 year old fig tree kept small by pruning |
A. Figs produce fruit very quickly after planting. You
should start seeing fruit produced the year after planting in most varieties.
Remember, figs produce fruit on the wood that grew last year as well as the
wood actively growing.
Figs can
be very big trees if you allow them to grow. They can also be cut back to a
much smaller size. You mentioned planting a grove of figs. Their planting
distances apart should be the same as their maximum height. If you plant them
10 feet apart, don’t let them grow above 10 feet tall.
Figs with early Briba crop and later main crop growing together |
Two Different Types of Trees: Palo Verde and Crepe Myrtle
Q. I have a Museum Palo Verde and a crepe myrtle planted
in the Fall of 2012. The Palo Verde has
grown well but the crepe myrtle hasn’t grown much in seven years. The roots of
the Palo Verde are now lifting the stone ring I built around it. Can those big
roots be cut out?
A. Palo Verde
I will tell you about cutting the roots at the end but let’s talk about your situation first. You have two different types of trees; the Palo Verde is native to the desert Southwest and considered xeric (desert adapted) while the crepe myrtle is native to the wetter and richer soils of South and Southeast Asia. It is considered mesic and not desert adapted. You can’t grow them the same way, under the same conditions, and have good results.
The Palo
Verde can handle the poor growing conditions of our desert while the crepe
myrtle must be pampered. Your crepe myrtle isn’t getting pampered that’s why
you have problems with it. These two trees are planted, managed and irrigated
differently.
The Palo
Verde will grow roots where water is applied to desert soils. If you water Palo
Verde 2 to 3 feet deep and let the upper foot of soil dry between irrigations,
the roots will grow mostly 2 to 3 feet
deep and not bother that stone ring lying on the surface of the soil. You
can control its rate of growth by giving
it lots of water occasionally and let the soil dry out before the next
irrigation. Every time it gets a deep drink of water, it will grow. When the
soil is dry, it does not.
The Palo
Verde is more forgiving of desert soil even when it’s planted badly. I’m not
saying it was or wasn’t planted correctly, but it tolerates bad soils better if
they are amended before planting. The Palo Verde will look better if it’s
planted in decent soil at the beginning, but how and where you apply water will
dictate how fast it grows and where its roots are located.
You
can’t do any of those things with crepe myrtle. Crepe myrtle will not tolerate
soils if amended badly at planting time. It won’t like the hotter and harsher
locations in the landscape. But Palo Verde will. Crepe myrtle will grow much
better if the soil is continuously moist and covered with 3 to 4 inches of
woodchips. Palo Verde will like this too, but it can sail through desert
hotspots and poorly amended soils better than crepe myrtle.
If they
are both on the same irrigation valve, then you will have a problem because the
Palo Verde will get water when you think the crepe myrtle needs it. They should
be watered separately. That would be too often for Palo Verde. It will grow
shallow roots because its watered too often. If these trees are on separate irrigation
valves, then the Palo Verde can be watered less often than the crepe myrtle.
Using separate valves benefits both of them.
Can you
cut off the roots of the Palo Verde that are causing problems? You can remove a
few of them each year for the next three years but start watering the Palo
Verde less often and give it more water with each of its applications. Get its
roots deeper and out of the way. Apply water to at least half the area under
the canopies of these trees.
Crepe Myrtle
Readers crepe myrtle |
On your crepe myrtle, I would put a ½ to
one inch layer of compost 12 inches away from the trunk to about three foot
away. You can get it bagged from Viragrow. I think you will need about ten bags
or less. Concentrate the compost closest to irrigation water or drip emitters
where it will get wet and decompose faster and move the leachate into the
ground toward the roots. The tree will respond faster if you can auger as many
holes as possible around the trunk to about 12 inches deep and fill them with
compost. Spreading it on the top of the soil will work but it will take longer
for the tree to get the benefits.
Cover that compost area with woodchips
about three to four inches deep. You can get them free from the University
Orchard in NLV (N. Decatur and Horse Drive) or their office complex on the
corner of Paradise Rd and Windmill just south of the airport. Call their Master
Gardener helpline at 702-257-5555 and make sure they have the woodchips
available before you go.
Then I would prune back the height of
your crepe myrtle and try to force some new growth lower on the trunk. Prune
the top back as much as possible while still keeping the growth on top. I am
hoping you will see some new growth lower on the trunk in the spring. This
growth will help strengthen the trunk and I am hoping you will not need to
stake it in a couple of years.
Plants to Replace Roses for Low Light Levels
Q. My roses are not doing good because there is no sun by
the wall where they are planted. Can you please suggest other flowers that can
be planted there?
From the look of the leaves in this picture you might need to amend the soil before planting roses. Roses appreciate amended soil in the soil surface covered in wood chips, not rock. |
A. Whenever you have a location in a landscape that’s not getting much sun, you can’t grow flowering plants in that location. They need more sun to produce flowers. Instead, focus on plants that do not produce flowers but are still ornamental. In other words, forget most flowering plants in that location. Flowering plants will need at least six to eight hours of sunlight to flower well.
All of these plants are mesic (nondesert) so make sure the soil is amended with compost at the time of planting.
Friday, December 6, 2019
Desert Horticulture References
Q. I am relatively new to this desert environment and I
know hardly anything about desert plants.
Would you recommend the best book(s) you have read that describe these
desert plants? Which are best as decorative lawn plants? When to plant them and
how to care for them?
A. I would focus on something written for the Las Vegas
climate or secondly Tucson, Arizona and lastly the desert Southwest. Books I
suggest are available on Amazon and Abe’s Books as well as other places if you
search using the author names.
Linn
Mills from Las Vegas and Dick Post from Reno teamed up and wrote a book called
the Nevada Gardeners Guide that has information split between both northern
Nevada and southern Nevada. Its focus was to understand both Mojave Desert (Las
Vegas) and Great Basin (Reno) conditions, soils and how to manage a landscape growing
in them.
Tucson
has a similar climate to Las Vegas; a bit warmer and humid in the winter and
wetter during the summer months. From here is Plants for Dry Climates by Mary
Rose Duffield and Warren Jones. It includes desert landscape design ideas as
well. The newest edition includes and expanded section plant selection and
care.
Adjust
books not written for the Las Vegas by recognizing that our winter low
temperatures can get into the low twenties and even the upper teens on
occasion. Trees you select for the “backbone” of your desert landscape should
withstand these temperatures or you are asking for trouble. Play around with
lesser important landscape plants that don’t tolerate these temperatures but
don’t expect them to survive forever.
A solid
reference book is the Sunset Western Garden Book. It is not specific for the
Las Vegas area but does a good job discussing desert soils, desert environments
as well as an exhaustive list of plants suitable for advanced gardeners.
I use
Chris Martin’s Virtual Library of Phoenix Landscape Plants, free online and housed
at Arizona State University, quite a bit. Just realize plants discussed are
used in the Phoenix climate and soils. Adjust your selection for our colder
winter temperatures and not as much heat in the summer.
Several
knowledgeable local experts like the Southern Nevada Water Authority (SNWA)
searchable database of landscape plants for Las Vegas, called “Find Plants”. It is a good online reference when first
looking for possible plants to use.
Creeping Thyme Between Rocks and Pavers
Q. Some time ago you mentioned a plant used
between stones or pavers, and when you step on it, it releases a fragrance. Can
you tell me the name of that plant again? I would sure appreciate it.
A. I don’t remember a specific ornamental groundcover that
I mentioned but creeping thyme will work, and it does come in culinary and
nonculinary types. You can direct seed it in those cracks by preparing the soil
with compost, watering the soil to settle it, lightly cover the seed with sand
and keeping the soil moist until you see it germinating.
You can
use creeping thyme for cooking in a pinch but use new growth. Don’t plant it in
extremely hot locations but it will work in an open area without reflected heat
from a south or west facing wall. Plant it just like you would in a vegetable
garden.
Can I Plant Texas Rangers Now?
Q. I recently purchased some Green Cloud Texas Rangers
from a building supply store and was wondering if it is safe to plant them now
since our weather is turning colder.
A, Since you emailed this question to me it froze in
parts of the valley this past week. But not to worry. This kind of weather can
be freakish this time of year. It normally does not freeze until the second
week of December. But the ground is still warm. After you plant you want the
roots to grow but you should not care about the top growing yet. The best
planting time for woody plants is from late September until mid-November. You
can still plant at other times but its just not as good because of root growth.
The
ground is still warm enough to plant. The magic number for landscape plant root
growth is about 50F. Of course, roots of plants grow faster in warmer soils,
but they will still grow at 50F. The ground never froze or was even close to
freezing. The soil temperature rises up and down mimicking the air temperature,
but these temperature swings are much smaller compared to air temperatures. For
instance, in some areas vegetables like tomatoes, peppers and squash froze, but
the ground never did. The soil in the ground was much warmer than the air.
If you
want the soil to warm up fast then keep it dark, fluffy, dry and in the sun.
Those kinds of soils have wide temperature swings from very warm to very cold
but still not as cold as the air. Landscape plant roots like to grow in those
warm temperatures during the day. Soils that are not fluffy, wet and instead
are covered by a surface mulch or in the shade stay cooler and don’t swing up
and down as much.
Surface
mulch keeps soils warmer in the Fall and cooler in the Spring.
I Want Larger Bartlett Pear Fruit
Q. I have a ten-year-old Bartlett pear tree and the pears
are kind of small, about 3 inches long. The label says they ripen in August but
mine are not ripe until end of October. November. I pick them, leave them out
in kitchen and they become juicy and ripe. I water the trees heavily once a
week and the fruit improve. Is there any way to make tree produce larger fruit?
A. Bartlett pear has the potential here for getting the
same size as in the stores with the same or better quality. It is a matter of
how many fruit there are compared to the number of leaves. If there are a lot
of fruit and not enough leaves to support the fruit, the fruit will be
smaller.
For
Bartlett pear you should have about 45 to 50 leaves for each piece of fruit so
that they can get larger. The fruit is produced on spurs that form an average
of five fruit per cluster. Remove all but one fruit per cluster when the fruit
has recently set and is still very small. This may be hard to judge when the
fruit is just starting out in the spring but try removing all but one of the
fruit in each cluster. If you want the fruit larger, next year remove more. Do
it when they are small. Don’t wait. The remaining fruit will get larger. This
is called “thinning the crop” or just plain “thinning”.
Fruit
also needs water present to expand and get big when its growing. Make sure the
tree gets adequate water while the fruit is enlarging. If the tree doesn’t, the
fruit will not grow as much. I don’t know if your watering is often enough or
not. But in midsummer I would guess the trees should be watered deeply two or
three times a week. Once a week is good in the Fall when it cools off.
Pick
Bartlett pears when they are still green, but the green has changed from dark
green to light green. Your label is wrong. Harvesting should be in about late
September or early October, not August. If you aren’t sure, pick one and cut it
open to look at the seeds. The seeds should be all brown then go ahead and pick
them. Picking may last two weeks as they don’t all get ready to pick at once.
Pick
the fruit before they turn yellow because this keeps the fruit texture buttery
instead of gritty. Then let them ripen in a cool place out of the sun until
they are ready to eat in a few days. When you get them from the store they are
sometimes green. Ripen them like that before eating them.
Irrigation Frequency of New Desert Ironwood Trees
Q. I have two desert ironwood trees that are ten years
old, 12 to 16 feet tall, in my landscape. A nursery told me I should water
these trees deep daily for 7 to 10 days. I did that and after the third day the
leaves turned a pale yellow and fell off to the touch, so I have stopped
watering. The soil moisture meter I use is showing 7 to 8. Any thoughts because
I really don’t want to hurt these beautiful trees.
A. When you call these trees “desert ironwood” I am
guessing you mean the ironwood native to the Sonoran Desert. It’s a beautiful
native desert tree that does not need to be watered very often. It is
considered an indicator tree for growing citrus so during cold weather in
southern Nevada it might get damaged. There are other trees called ironwood as
well.
Because
it grows in the desert, it is not used to getting water very often. When you
water this tree, irrigate the area under its canopy to a depth in the soil
about 18 to 24 inches. Then don’t water again until the soil dries out. Because
it’s a desert tree, it will not like wet soil but soil that occasionally gets
wet. That’s why the leaves are yellowing and falling off; watering is too often
and the roots are suffocating.
On the
soil moisture sensor, or meter that you have, the needle should be in the three
or four spot before you water again. The meter reads zero to ten with ten being
sopping wet. You want the soil to be on the dry side about six inches deep, not
the wet side when you water it again.
When
you do water, try a hose, an inexpensive sprinkler that screws onto the end of
the hose and a mechanical timer that shuts off the water. If you are like me, I
forget to turn it off. The mechanical timer will shut it off for me. Set it for
one hour. Take a length of rebar and stick it into the ground in three places
and make sure the water got to the right depth. If the water isn’t deep enough
then water for 15 minutes more.
I Want Plants That Bloom All Season Long
Q. I am looking
for plants that bloom all season long like lantana. Can you help me?
A. I would rather that you use a searchable plant
database online like the one created by Southern Nevada Water Authority. It’s a
good one. Google or use your favorite internet browser and type in “find plants
SNWA”. The Sunset Zone for Las Vegas is Zone 11. The rest of the information
needed for the database should be straight forward. Use this before you go to
the nursery and get a list of plants that you want.
If you
want plants selection advice from me, ask for five suggestions at your nursery
and then I can help you pick which might be best. There is a lot of information
available to help you decide. Select trees and shrubs that you cannot afford to
lose using a minimum winter temperature of 20F. If we have a few warm winters
in a row then you won’t lose anything!
If
you select plants that tolerate winter temperatures above this temperature then
expect to lose them occasionally during cold winters. Even at 20F we will have
30 to 50-year freezes that will get as low as 12F. If the 20F plants are
established in the landscape well before that, they will probably survive.
Should I Add Worms to My Raised Beds?
Q. I made a couple of raised bed planters for tomatoes and
peppers and currently have garlic, spinach and lettuce growing. Would adding
worms to the soil help?
A. Worm benefits far outweigh any feeding damage they do to
plant roots. I know I will get some heat for saying this, but earthworms can
create some damage to small plant roots. Just like ants can carry away seeds
that you plant. Too much of a good thing can be too much.
If
you do add some earthworms to your garden plot, you don’t need to add many.
They multiply quickly when organics and moisture are present. The addition of
compost to raw desert soil and growing plants in it is usually enough. I will
see earthworms in soils that I amend and cover with woodchips in abundance the
first year after planting. Adding worms to your soil will speed up what will
occur naturally.
Spider Mites on Italian Cypress Is a Hot Weather Problem
Q. My Italian cypress had spider mites, so I sprayed the
trees with an insecticide about six weeks ago. Nearby Italian cypress trees are
also full of spider mites. I was going to spray them with an insecticide until
I listened to your Desert Horticulture podcast which told me to use a miticide
instead. Which one should I use?
This Browning could be from spider mites, watering too often, or borers. If it occurs in the middle of summer it's very likely spider mites. |
A. Spider mites are a hot weather insect so spraying when it's not summer just for them doesn’t make much sense. However, spraying oils in Fall and
Winter months makes perfect sense for insects that might spend the winter on
your trees.
Horticultural oils, sometimes called dormant oil or spray oil, is the best insurance to prevent insect outbreaks like aphids, spider mites, and scale insects. |
Remember,
spraying insecticides make mite problems more likely on susceptible plants like
Italian cypress. Miticides, unlike insecticides, are less likely to cause mite
problems later. Spider mites are nearly always present on all plants they feed
on. There are lots of insects that feed on spider mites as well and keep them
in check.
Spider mites, like their name suggests, usually leave a webbing that you can see when there is damage. |
These
predatory insects hunt down spider mites and use them for food. Think coyotes
and rabbits. Spraying traditional insecticides like Malathion, Sevin and even
organic insecticides like Neem oil or soap and water kills most insects off,
good ones as well as the bad one you wanted to control. The primary benefit of
organic sprays are its environmental safety and short life after its sprayed.
If an
insecticide must be sprayed for some reason, watch the sprayed plants very
carefully during hot weather to see if spider mites become a problem or not.
Frequently spider mites will become a problem after spraying an insecticide
because their predators were killed. I realize sometimes you must, but spray
insecticides as a last resort.
Close-up of the needles or foliage of Italian Cypress and spider mite damage. |
Miticides
are chosen because spider mites are more like spiders than insects and sprays
that kill insects oftentimes don’t kill spider mites. I am glad you did not use
an insecticide for mite control. It would have made the problem worse and probably
not killed the spider mites.
Use the
University of California Integrated Pest Management websites (“Google” them by
using your favorite search engine and typing in “UCIPM” and “spider mites”).
Read these notes. They are written by entomologists who specialize in
controlling pests. After reading these notes you will be better informed than 90%
of the landscapers spraying plants.
The
UCIPM notes will recommend spraying oils like canola, clove and cinnamon oils
as well as horticultural oils and sulfur sprays to control spider mites. In our
hot desert environment these sprays may damage plants during the hot months. It
is cool enough in the Fall, Winter and Spring you can spray oils without damaging
most plants. Plants that may be damaged will be listed on the label.
Didn't Think Italian Cypress Got Borers. I Was Wrong!
Q. I had a lot of borer damage to my trees so last summer
I cut out most of the large branches and reduced the height of the trees to
about 10 feet and let them grow back. Then I treated the soil with an
insecticide, surfactant and fertilizer. That was my counterattack regarding the
borers.
Borer exit holes in the trunk of Italian Cypress sent in by an alert reader. |
A. Make sure trees that you do cut back will grow back.
Some trees like most ash trees will not grow back very well if they are pruned
severely. Also make sure the pruning instruments are all sanitized before
pruning.
Insecticides
like Imidacloprid (active ingredient) used as a soil drench (mixed with water
and contained on the surface of the soil above the roots) are systemic and
taken up by roots of the tree and kill many types of borers. Whatever
insecticide you use should be systemic and have a label that says it is
effective against wood boring insects.
If the insecticide
has “staying power” inside the tree then I would apply it after the tree
flowers. This is usually in early spring. Long-lasting, systemic insecticides
like Imidacloprid are suspected to harm honeybees. There is a possibility the
insecticide could be available to honeybees if it is applied just before
flowering.
A portion of the product label for Imidacloprid 2F warning about killing honeybees. Be careful when you spray insecticides or apply them as a drench to the soil. |
One example of a surfactant. When mixed with a spray it helps the product get inside leaves or stems. When mixed with a liquid drench it might help the drench move into the soil better. |
Pruning Heresy for Italian Cypress
Q. My Italian cypress are getting too tall. Can I top them
to keep them smaller?
Here a homeowner "topped" their Italian Cypress to control its height. It works but it will increase the width of the tree through new growth to the sides rather than directly upward. |
A. Topping trees is not a good idea but in this case it
will work because underneath all that foliage is a central trunk. It’s not the
best way to handle this dilemma but if it is done when the tree is smaller it will
help prevent it from getting too tall. Removing several feet of the top this
way is questionable.
Remove
the pointed top just below the height wanted. This keeps the tree’s height in check,
but it will grow wider than if it were left alone. Hindsight is 20/20. It would
have been better to realize these are 40 to 60-foot trees before buying or
planting them.
The bad
pruning method is shearing the tree with a hedge shears. Shearing does prevent
long “floppy branches” from developing but it causes other problems. Shearing
increases the density of the tree in the outer few inches while the inside branches
become naked. The inside of the tree gets darker and darker as shearing increases,
and this prevents any greenery from forming.
Be Careful Watering Italian Cypress
Q. I am purchasing some Italian cypress as a visual
barrier between my neighbors and myself. I understand they are evergreen. Any
thoughts?
A. Italian cypress is a big tree so make sure you have room for it, and it is in scale with your home and landscape. It can be 40 to 60 feet tall and 4 to 8 feet wide. It is a good visual barrier but tall!
Italian
cypress is a Mediterranean plant, not a desert plant. This tree came from
climates with cool wet winters and hot dry summers so don't water too often but
more often than true natives! Put it on a valve that waters palms, fruit trees,
other landscape trees and shrubs but not with lawns, flower beds or vegetable
beds. It will not like it if it is watered with the same frequency as cacti and
native desert trees like Palo Verde and mesquite unless they are watered too
often!
Italian
cypress with long drooping branches is a sign it is getting too much water.
Either it is watered too often, or the soil is not draining water fast enough.
Hedge shearing (not recommended) keeps them in check but using a hand pruner
instead is a better option.
Shearing them with a hedge shears is one method to make them look pretty and keep them in bounds. But that is expensive to do twice a year. |
How Far Apart When Planting a Hedge?
Q. How far apart should I plant my hedge shrubs to make a
hedge?
A. It depends on the plant but a general rule of thumb
for shrubs that grow just as wide as they are tall is to plant them the same
distance as their mature height. If you plant them this far apart they will
grow up touching each other. If you want them to fill in faster, then plant
them a bit closer.
Pruning shrubs with a hedge shears tells me you don't know how to prune. |
Planting them too close together causes them to grow together but they will shade each other. That’s not a problem for the hedge but you will spend more money than you need to in plants.
Thursday, December 5, 2019
Transplanting Sago Palm - Do it Right
Q. Do you have any advice on digging and transplanting a
Sago palm this time of year? It’s the roots I’m considering. I failed last time
maybe because it was too hot.
Nicely cared for cycad or Sago Palm |
A. The ideal time to move sago palm, or cycad, is in the
early Fall or early Spring but you can do it now even though its cold. It’s
just not optimum. Evaluate your situation. If it has been in the ground more
than three years, it is more difficult to move without damaging it. It helps if
it was drip irrigated with no other irrigation within 10 feet or so. This
isolates the roots and keeps what you need to move closer to the plant.
These plants like a little bit of shade or protection from late afternoon sun. They just do better. |
Two
things are important when you move a plant: take as much of the roots and soil as
possible during the move and reduce the top by 1/3 to compensate for root losses
during the relocation. You will have more success if it is moved into a spot
with light shade, not full sun.
Here’s
the process. I will put more information on my blog for you.
Cycad transplanting process
- Remove fronds from the bottom toward the top so the remaining fronds are no more than a 45-degree angle from horizontal. The central fronds should be protected. The older palm fronds can be removed. Sago palm grows from the center straight up and the fronds become lower with age. Mark which side of the plant faces north. You will orient this side to the north again when planting.
- Prepare the soil and hole in the new location so you can place it into its new home and plant it as quickly as possible. The hole should be about the same depth as the rootball you are moving. The hole with amended soil will be much bigger.
- Move everything away from the sago palm so that it is surrounded by bare soil and then water the soil until it is sopping wet. Using a sharp, clean shovel, slice the roots of the palm at about 12 inches from the trunk. Otherwise, leave it undisturbed. The next day after water has drained, leverage the plant upward carefully from its old location while cutting any remaining roots that might hold it back.
- Placing the rootball and plant on an old piece of carpet or strong fabric by lifting the rootball, carefully move the plant to its new location without breaking the soil around the rootball. Very important.
- Orient the sago palm with the north side facing north and backfill around the rootball using amended soil as a soil slurry to remove air pockets. It will not need to be staked. Add any amendments to the soil you feel is necessary to improve rooting. I personally don’t use anything more than the amended soil.
- After the soil has settled and starts to dry, cover the area surrounding the sago palm with woodchips. Woodchips are a better soil covering (mulch) than rock for sago palm.
Plant During Winter but Not As Good As Fall Planting
Q. I would like to plant a pomegranate tree this Fall but
I am worried that the weather is going to be cooling down soon. Do you think I
missed my opportunity for planting, and should I wait for Spring?
A. Just because it is getting colder doesn’t mean you
can’t plant. Ideally you want a few weeks of root growth in the Fall after
planting. The timing may not be optimum for root growth when soil temperatures
are cold, but it will still work out. If you find a variety you like, get it in
the ground.
Temperate
plant roots (like pomegranate) grow best when soil temperatures are between 60
to 75F but they still grow even when soil temperatures are as low as 45F. They
just don’t grow as fast. Try to plant early enough so that there are 4 to 5
weeks of warm soil temperatures before the soil gets cold.
Estimating soil temperature
How to
estimate the soil temperature? The best way is to buy a soil thermometer for
about $15 and measure for yourself but otherwise you can make a rough
approximation.
Soils are always a bit
warmer than air temperatures. Take the average air temperature over the past
couple of weeks (low + high and divide by two) and add 5 degrees. Surface
mulch, rock or woodchips, conserve soil warmth in the Fall and insulate soil
from heat in the Spring and Summer months.
In my
experience, using your sense of touch is accurate to within about 5 degrees F
of temperatures ranging from the refrigerator (40F) to the spa (105F).
Fall
planting is always superior to Spring planting of winter hardy plants.
Steer Manure Is Stinky but Can Be Used
Q. We applied Red Star steer manure as a topsoil during
overseeding tall fescue three days ago. Is it ok to apply granulated fertilizer
to this or should we wait longer?
Stinky Steer manure can be used for top dressing seed in a lawn or even vegetable garden but let it age |
A. So we are on the same page on this, you are spreading
some seed on your tall fescue lawn to increase its density, thickening up some
thin areas and maybe improving the look of your lawn because of some brown
spots or dead areas. Once the seed is spread and fertilizer is applied, you are
spreading a thin layer of steer manure as a “topdressing” (you are calling it
“topsoil”) to improve the germination of the seed. The best time to do all this
is from about mid-September to mid-October. It is getting late now.
Manure used for topdressing
Bagged
steer manure was used in the past as a topdressing for lawns when overseeding.
It was smelly but it worked well. Years ago, you knew it was fall overseeding
time because of the steer manure smell in the neighborhood. Now there are
commercial topdressing products available but bagged steer manure still works.
Rules for overseeding
In lawn
seed germination, a rule to follow for good seed germination when overseeding
lawns is good “soil and seed contact”. It is important that the seed applied is
in contact with the soil after the application is done. The steer manure or topdressing
was a “blanket” that pushed the seed down and helped keep the area moist.
Make
sure the lawn is mowed as short as possible (for fescue I wouldn’t mow shorter
than one inch) and any debris on the soil surface (thatch) is disturbed or
removed. This is done with a dethatcher, power rake or verticutter. This can be
done by hand using a garden rake or gasoline driven if it’s a large area. For
best results you should see bare soil when you are finished.
After
the lawn has been “dethatched” is the best time to apply a starter fertilizer
for overseeding because it is high in phosphorus. This fertilizer is applied at
this time, so it lands on bare soil along with the seed used for overseeding. The
phosphorus is the part of the fertilizer you want on the bare soil because it
doesn’t help the seed as much if it is applied after the job is finished.
Phosphorus fertilizer should be mixed into the soil
Remember this in the future. It’s the same fertilizer used in vegetable gardens
during soil preparation prior to seeding or planting vegetable transplants. The
final application is a thin layer of topdressing, in your case the steer
manure.
Applying
a starter fertilizer after it’s all finished is not the best but better than
nothing. Go ahead and apply it. It’s not optimum but it will do some good as
the seed is germinating and taking root.
Watering Lantana and Roses in the Mojave Desert
Q. I need suggestions for watering times and days to
water in the summer for sprinklers watering trees in lawns, lantana bushes and
rose bushes with drip irrigation.
It isn't just the watering that's important for roses but soil health is well. Lantana is much more tolerant of rock and poor soils than roses. |
A. When watering trees in a lawn, give the trees extra
watering separately from the lawn since the trees should be watered more deeply
than the grass. In the summer do this about every two weeks in sandy soil, less
often in heavier soils.
- Grass is watered 8 to 12 inches deep
- while small trees (less than 20 feet tall) are watered 18 inches, deep and
- medium height trees (less than 40 feet tall) are watered 24 inches deep. This can be done with a sprinkler on the end of a hose and a mechanical timer. This improves tree growth and establishment if the lawn is being watered carefully.
Watering
times for other plants are also suggested by your water provider. Lantana is a
shallow rooted small woody shrub. It should be watered about 12 inches deep and
no more than every other day in the summer. Water all its roots on one day and
then hold off at least one day before watering again. Lantana will tolerate
rock covering the soil surrounding it. Just make sure you apply fertilizer
about three times each year. When the top turns brown, cut it back to 1 to 2
inches above the soil.
Roses are different. Watering frequency is the
same as lantana, but they don’t like the soil covered in rock. They like
woodchips that disintegrate, covering the soil surface, and surrounded by soil
that is rich. Plant them in amended soil and keep the soil covered with
woodchips.
Cutting Off Roots from Trees is a Judgement Call
Q. When our landscapers installed new water lines for
irrigation they cut through two major roots on a Chitalpa tree; one root was 4
inches in diameter and the other 1 ½ inches in diameter. These water lines could
have been installed under the roots instead of cutting them. I am not sure why
they did it this way. I am concerned about the future health of the tree.
A bit hard to see but a large Chitalpa root cut by landscaper. |
A. If this is a problem for the tree, is a difficult
question to answer. Will cutting the roots of a tree cause it to die? Cutting
tree roots always damages the tree. Can the tree recover from this damage? The
right answer is, it depends. From your description, the root removal done
sounds ominous.
Tree roots grow where water is applied. If water is applied in shallow irrigations, it leads to shallow roots. |
You can typically remove about one
third of the total roots with no problem. This is done sometimes when trenches
are cut in the soil for burying irrigation lines. When roots are cut. But when
roots are cut, about 1/3 of the top should be removed as well. This removal of part
of the top puts the top and roots back in balance with each other. How much of
the total roots were removed in your tree’s case? That is difficult to estimate.
Strangling roots should be removed as young as possible for obvious reasons. |
Look at
the distribution of water applied for irrigation. This helps determine where
the roots might be. Roots grow toward water because the soil is wetter in these
locations. If there is a lawn close to the tree, then roots grow vigorously
toward the lawn and less vigorously toward its own drip emitters. If other
plants are growing near the Chitalpa, tree roots will likely grow toward the majority
of drip emitters because there is more water there.
At the
very least, remove about 1/3 of the top. Remove entire limbs rather than giving
it a “butch haircut” and removing the ends of lots of branches. Removing two or
three major limbs is probably enough in your trees case.
This native mesquite near a river in Jerez, Mexico, sent its roots deep after underground water coming from the river. |
As a precaution, I would stake this tree. Major roots of trees are used for tree stability particularly during strong winds. The tree might need to be staked until the roots secure the tree in the ground. I would do it in case it is needed. Don’t wait until the tree starts to lean because of strong winds. Remove the stakes when the tree is stable. This might be one season of growth for smaller trees or up to three years for larger trees.
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