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Wednesday, October 29, 2014

Viragrow Delivers! : Some Recommended Vegetable Varieties for Fall and ...

Recommended Vegetable Varieties for Fall and ...: Our garden group got together this past Saturday and started putting together a recommended vegetable variety list for the Mojave Desert. So...

Viragrow Delivers!

Tuesday, October 28, 2014

Fig Fruit Drop May Be Lack of Water

Q. After reading your suggestions I have a feeling the problem could be not enough water.  What do you think?  I have been watering three times a week for 1 1/2 hours (8 gal. each hour) for a total of 12 gallons each time. I took a picture of the fig tree so you could get an idea on the size of the tree.  As you can see the tree is mulched.
Readers fig tree
A. A very reliable indicator that a fig is not getting enough water is poor fruit development. Fig is a very resilient plant when it comes to water and can withstand fairly droughty conditions. But one of the first things a fig will do when water is limiting is hold back on fruit production or produce fruit that is not “juicy” because that requires lots of water. 
Figs produced along the Brown older wood. This is the first crop produced on the wood from last year. This is called the Briba crop.

Fig fruit will be small and tough if not enough water is applied. When water is withheld even further then you will see the results in growth. At this point fruit production is no longer in the picture much but rapid and wild growth will be curtailed. Figs need new growth for fruit production. The more growth it has, the more fruit it will produce on this new growth. New growth becomes the source of fruit production this year and early fruit production (Briba crop) next year. Once fruit production is over you can pull back on watering but it needs plenty of water when fruit is being produced.
Figure leaf yellowing and leaf drop can be a sign you need to give more water
It is hard for me to tell if your watering is adequate or not. The frequency, three times a week, sure seems enough. The quantity of 12 gallons each time sure sounds enough for a small tree like that. Without going down to the roots somehow and seeing if the soil is moist or not we are just guessing. Mulching helps but a small amount of mulch around the trunks a couple of feet in all directions and an inch thick will not be enough most likely. I like to put down mulch at least four inches in depth and have it out as much as the edge of the canopy (where the growth stops) to be effective.

But the proof is in the pudding. If fruits are not swelling up to a good size and full of water my guess is that something is keeping the water from getting to the fruit from the roots. Either not enough is applied or often enough or there is something stopping the water from getting to the fruit such as root damage, trunk or limb damage, disease or insect problems.

Parrys Agave Good Choice for Mojave Desert Landscapes

Parry’s Agave
Andrea Meckley, Certified Horticulturist
Description:  Evergreen succulent
Mature size: 2’x 2’
Flower:  with aged plants
Water use:  low
Exposure:  all day sun
Origin:  Arizona, New Mexico, and Northern Mexico
Parry's Agave
Hardy:  to 5 degrees F
Uses:  Landscape accent plant, potted plant

One of the many hardy agave species for our southwest landscapes and gardens is Parry’s agave (Agave parryii).  The grey green leaves grow slowly as a compact rosette.  Adding interest are patterns of indentations of previous leaves showing on the back of each new leaf.   In late spring to early summer old Parry’s agaves, 20 years or more, produce a twelve-foot stalk of blooms that can grow four inches a day. Hummingbirds are attracted to the flowers which begin as red or pink buds, opening to a bright yellow bouquet.  The plant dies after blooming but during its lifetime produces offsets assuring more plants will replace the original.   Planted in groups or alone this plant is attractive in the succulent garden, in pots, or in the landscape.

Readers Success with Sago palms and Saguaro in Las Vegas

After reading your column in the R-J for 10/25-26, specifically your response to a question about Sago palms, I thought I would share my Sago success with you. To summarize, the main plant in the 1st picture was started from a "pup' off of a neighbor's plant in La Verne, CA, in 1972.  

The 2nd pictured tree began as a "pup" from the 1st one.   I kept both trees in 5-gallon rolling redwood tubs with full exposure to afternoon sun.  When we moved to Tucson, AZ in 1994, the tubs went with us.  I then moved the trees out of the tubs and into the ground where their exposure was pretty much limited to the morning sun.  When we retired and decided to relocate to Las Vegas in early 1999, both trees were moved back into redwood boxes and made the relocation with us.  After substantial changes to our new backyard in Las Vegas were completed in early October 1999, I once again moved the trees into the ground.  For esthetic reasons, I have allowed both trees to keep "pups" of their own.  These trees have a main exposure to the south and receive direct sun all day.  

The 3rd picture is a view looking from the WSW and captures both trees.  I think they are both doing quite well.

Another plant we are quite proud of is the Saguaro cactus shown in the last photo.  This plant, which was in the ground at our new LV home in early 1999, was just under 2 ft tall.  During the course of our backyard remodel, this plant was moved 2 times before its present location while being very careful each time to maintain its "clock" orientation...lessons learned from our Sonoran desert experience.  The rear fence is 5-1/2 ft tall to give you a perspective of the trees's height today.  You will also notice the arms that have emerged...4 that you can see with 2 others on the far side.

I trust you will find this Sago success story interesting and enjoyable.

Reader Success with Celebrity and Beefmaster Tomatoes in Las Vegas

I received this email from a reader who wanted to tell me about some of his successes. The following are his successes with some of the pictures he sent to me.

This year I planted Celebrity & Beefmaster, one each in hanging planters and one each in our little raised garden.  I can tell you the hanging planters are a waste of time and money.  We got maybe 6 or so tomatoes off the two plants and none were even 3" size.
Readers Beefmaster tomato in small raised bed
In our raised garden the other two plants gave us a pretty good harvest with tomatoes from late June to early August.  I think I need to put even more straw for the Celebrity.  The Beefmaster gave us actually bigger tomatoes and they gave us more, but they sometimes were a strange shape, although the taste was great.
Readers Celebrity (smaller, round) and Beffmaster tomatoes
What I really wanted to relay is the story about the tomatoes shown in the photo.  These were picked a few days ago in early October.  As I said the plants were planted in early April, I was late this year.  They stopped producing around mid-July.  I was going to remove them and put in new plants but ran out of time as we left for travels to Europe in late August. Surprise!!  

When we returned 1 Oct these two plants had continued to grow (see other photos in separate emails) and were bearing new tomatoes as shown.  The plants are huge, probably at least 10 feet in height/length, leaning over due to the weight.  The Celebrity has produced the smaller tomatoes.  The Beefmaster is still producing large tomatoes, but they do have shapes just a little different than beefsteak, but they do remind me of such.  Served some at a dinner party last weekend and all were amazed at the get taste.

There are still at least 12-15 tomatoes on these two vines, currently all green, bit they continue to ripen.

i just think it great to continue to have fresh vine ripened tomatoes this time of year.

Desert Green Conference for Landscape Professionals Nov 6-7

Desert green conference for professionals will be held on November 6-7 at the Henderson Convention Center. Tell your gardeners about it and encourage them to attend. There are many good presentations made to help local gardeners become better at their profession.

Click here for more information about the Desert Green Conference and Regisrtation

Click here to see the conference agenda and Registration

Chinese Pistache Leaves Curling

Q. I have a Chinese pistache tree which is nice and green but the leaves began to curl. I spoke to someone at the nursery where I bought it, I did what they said but I am not seeing any change yet. Can you help me save my tree that cost me so very much money when I had them plant it last year?

A. Chinese pistache is a tree that does very nicely in our desert climate with very few problems. One thing that it hates is a soil that stays wet.
Curling leaves on pistachio can be an indicator of a water or insect problem. Once the leaves are curled however, these leaves will not straighten out again. However new leaves that come out should be normal if you have corrected the problem.
Curled leaves can indicate water stress; not enough water in the soil or watered applied to often. If watered too often, curled leaves can be an indicator of root rot or trunk rot at the soil level which is called collar rot which results if the soil is kept constantly wet or it is buried too deep.
Whatever you do, be sure not to water this tree daily! You will kill it if you do. You are far better off giving it more water than it needs, but applying less often.
The amount of water to apply depends on its size. How often you applied the water depends on the time of year. In midsummer you should not be watering more often than three times a week. For desert adapted trees like this one you should be able to get by on one, or at the most, two watering's in one week.
I wish I could tell you how many minutes of water to apply but water does not work in minutes, it works in gallons. If your tree is watered by drip irrigation, you should have four drip emitters around the tree.
Once the tree is above 10 feet, you should be adding more emitters around the tree. The emitters should be no closer than about 18 inches from the trunk.
If the problem is from insects feeding on the leaves and causing them to curl, a systemic insecticide intended to be applied to the soil above the roots should kill the insects. The leaves that are curled will stay curled. You will not see normal leaves until you see new growth. 

Eggplant Beautiful Bush No Fruit

Q. I have grown plants in whiskey barrels every year with a good harvest. This year my eggplants have grown bigger than ever, beautiful, look healthy and have lots of purple flowers but almost no fruit. Since planting it's just been one giant flower bush. Why is it not producing fruit?

A. I am guessing it is a combination of probably three things; variety, weather conditions and general care. Stick to varieties of eggplant that have done well for you in the past. Don’t just buy any eggplant off the shelf and expect the same results. Varieties are important.
Purple Thai eggplant, a good variety for the Mojave desert if you like Asian style eggplant
Secondly is the weather. At very high temperatures many vegetables will fail to set fruit. This is because the pollen may become sterile at high temperatures and the fruit will start to develop and fall off. Some varieties are better at setting fruit at high temperatures than others.
Thirdly is soil enrichment and fertilizing. If your soil has been amended with a good quality compost prior to planting then I would not fertilize with any nitrogen fertilizer until I saw fruit developed that was a couple of inches long.
Eggplant forming fruit in July
If the soil is enriched heavily with good compost and then we fertilize the plants with high nitrogen fertilizers we can end up with wonderful vegetable bushes with little to no fruit.
I would suggest you mulch the plants as well. This will help keep soil moisture more constant. If soil moisture goes up and down during the day, the plant may drop flowers or fruit as well.

Less likely is a lack of bee activity. I am guessing your bee activity has been about the same as previous years so that it is not likely to be the problem.

Azalea Problems in the Desert

Q. We have an azalea planted on the northeast side of the house.  At this time of year it gets no sun. The tips of its leaves are brown.  What needs to be done?

A. Azalea is a very difficult plant to grow in our climate and soils. It likes soils on the acidic side, with lots of organic matter in the soil, absolutely hates salts and salinity, does not handle direct sunlight very well at all in the desert, in short it is one of the more difficult plants to grow here.

That being said, I also planted one about 30 years ago in a very similar exposure. It did the same thing as yours and that is the leaf tips turned brown or died after about three years.
If you are going to try and make this work to any degree at all your exposure would be okay but you have to modify your soil with lots of good compost, finally ground sulfur or aluminum sulfate to help lower the pH of the soil and wood mulch.

Make sure you have enough water surrounding the plant so that the soil doesn't dry out. If this were my plant I would push any salts out of the soil surrounding the roots by letting the hose slowly run water around the base of the plant for several hours so it is completely drenched. I would wait two or three days and do it again.

The purpose of this is to push out any salts that may have accumulated around the roots. I would check to make sure that there are enough drip emitters, if that's what you're using, to thoroughly wet the soil around the plant every time it irrigates. If not, I would add some.

Next I would lightly dig in around the base of the plant some good compost mixed with finely granulated sulfur and some iron chelate.

Next I would look for a specialty fertilizer for azaleas and fertilize the plant lightly this fall. If this were a water-soluble fertilizer I would mix it in a bucket of water and pour around the base of the plant. I would repeat the fertilizer application in the spring.

Finally I would cover the soil under the plant with a couple of inches of wood chip mulch. The old believes that have scorched tips will remain on the plant until you get some new growth and they finally drop off.

Read another point of view about azaleas in the desert

Wormy Artichokes a New Problem?

Q. What is the worm or caterpillar that attacks artichoke plants and how do I control them?  I had a beautiful artichoke plant last year and had four or five great artichokes from it right away. Then the worms (caterpillars) struck and were all through the artichokes. I cut it down and it came back beautifully but now the worms or caterpillars are eating all of the leaves.

A. This is most likely either damage from armyworms or loopers. I am guessing that it is probably armyworm.

It doesn't matter which one, the control measures are the same just the timing could be different. The usual time we see damage from armyworms is either in the spring of the fall. They can attack the leaves or the flower buds. Loopers crawl along like the cartoons of caterpillars where the midsection “loops” up in a curve. Armyworms don’t.
Spinosad as a liquid that can be attached to a hose for an application.
You would use either a spray of Dipel, Thuricide or Spinosad. All three of these sprays are considered organic and do a very good job on these types of critters. Their death is not immediate but they do stop feeding a very short time after these sprays come in contact with them. They will die a couple of days later.
BT in the form of Dipel as a dry, flowable insecticide. This one must be mixed in water and constantly stirred or agitated to keep it suspended.
If you see them now, spray. Mark your calendar for next year and spray when you first start to see damage. You can apply a preventive using your calendar as a guide when to apply.
Bt in liquid form

These sprays are good to have around since they can be used to control a number of different “wormy” pests on tomatoes, peppers, eggplant, grapevines, fruit trees, petunias and many other plants.

Read more about pest management in artichoke

Fall Or Winter Head Cold or Allergies? Shoestring Acacia.

Shoestring Acacia is in bloom right now and has been credited with allergy problems. In fact, they will bloom through most of the winter.
Shoestring Acacia flowers in Bloom in January
Shoestring Acacia can grow up to 40 feet tall quite rapidly and it is relatively upright so it can be useful in more narrow locations and in scale with two-story homes and commercial buildings.They are good selection for desert landscapes but allergies might be a problem.
Shoestring Acacia with a fairly wide form.
It is propagated from seed so there is a lot of genetic variability which means you can have narrow ones and you can have wider ones. If you are picking one that is intended for a narrow area, pick one that has a narrow habit to begin with in the nursery. Chances are if it is narrow in the container it is more likely to be narrow when it is older. If you pick one that is not so narrow when it is small, you do run the chance of having a fairly wide Shoestring Acacia.
Shoestring Acacia, narrow form. This tree is started from seed so there is a lot of variation in the trees. Pick one that is narrow to begin with and hopefully it will stay narrow if that is what you want. If you want one that's wide, then pick a form that's wide in the nursery.

It hails from Australia which, like so many trees from Australia, blooms during the fall or winter months rather than spring and summer. It is popular here in the desert Southwest and some people consider that it might be over planted.  There are complaints from people that it is messy and the leaves, because they are long and narrow, are difficult to clean up. Whatever you do, don't cut the top off. Trees that are pruned like this are ruined for life.
Shoestring Acacia topped at commercial planting North Decatur and CC 215

Monday, October 27, 2014

Tuesday, October 21, 2014

Can Sago Palm Grow in the Hot Desert?

Q. I understood that sago palms liked afternoon shade.  Can this plant handle afternoon sun with reflected heat and rock mulch?
Sago palm or cycad in planter in desert landscape

A. Sago palm or cycads will perform better with less care if they are planted in eastern or northern exposures rather than southern or western exposures. They will survive in your spot but will not look their best.
They will grow in full sun and under some very tough desert conditions if the soil is improved, they are receiving the right kind of irrigation and fertilizer and surrounded by wood mulch. 
Sago palm growing in partial shade in the desert
When grown under these very harsh conditions they usually grow shorter fronds, the fronds are frequently discolored with a yellowish or bronze appearance and the fronds may even scorch or burn at the tips.
When these plants are grown in more protective environments they look much better with more succulent growth, longer fronds, darker green with a lot less care. It would be incorrect to say they will not grow under some very harsh conditions but they will perform better and with less management in less hostile environments.

Will it survive with rock mulch in an intense desert environment? Sometimes. But it will not have a long life expectancy and not look as pretty. Under rock mulch conditions with very little soil improvement I would give them 5 to 10 years looking okay after they were planted. 

What is Causing the Webbing in My Desert Willow

Q. My desert willows in Kingman, Arizona, are being eaten up by worms. The web-like pods are all over the branches, but I have not found anything inside. I certainly do not want to spray as the trees are over one of my gardens and close to some windows.

A. I did some quick checking but could not find this critter mentioned anywhere. How do you k now they were being eaten up? It is possible they have done their damage and now have moved on leaving their webbing behind.
Sphinx moth found dead on sidewalk in May in Las Vegas.
Desert willow is used in butterfly gardens but it is usually for the adult butterfly rather than the immature larva (worms) or caterpillar. If they are causing a great deal of damage then they should be controlled.
Tent caterpillar webbing
Worms or caterpillars that do cause damage to desert willow are the Sphinx moth larva or “worm” and relatives of tent caterpillars. The larva of the Sphinx moth is gigantic with the horn coming off of its rear end. You would've recognized that one if you had seen it.
Sphinx moth to give you perspective on size of the moth.
Bt formulation from Monterey
The other caterpillar is much smaller, along the sizes you're talking about, but they usually form a webbing one or 2 feet across and they feed inside this webbing or tent. That's why they call these “tent caterpillars”. Tent caterpillars reproduce quickly and do a lot of feeding over a short period of time.
My guess is that these critters will not last very long and be on their way for the season. The desert willow will respond and survive. But in the meantime that tree will have some damage.

You could use a spray of BT, called usually either Dipel or Thuricide which is an organic control. It will only target “worms” that become moths or butterflies. Also Spinosad will work as well. This way you could avoid more poisonous conventional sprays.

Use Five Gallon Buckets in Place of Drip Irrigation

Q. My pine trees are over 20 years old and very tall.  I looked on the net and found a YouTube video out of Kansas showing a man using a 5 gallon bucket with a pin hole in the bottom for the purpose of watering them. I called my landscaping guy and he said that I am wasting water by watering that way.  Am I doing right by watering with buckets or is he correct about this method?

A. Using a bucket with a small hole in it works just like drip irrigation as long as the holes is small enough that it lets the water out very slowly. Using buckets is similar to the very first form of drip irrigation which was sinking unglazed ceramic pots into the soil.

Series of pictures showing what the reader did after getting a few ideas here on how to water his large pine tree with buckets.
You will have to fill the buckets two or three times each time you water to get the water deep enough in the soil to encourage deeper rooting. Don’t water again for about a week at this time of year; less often in winter and maybe twice a week in the heat of summer. Deep watering helps avoid the development of large surface roots that can heave sidewalks, driveways, walls and foundations.
This type of system accomplishes the same thing as a drip system but with more work on your part and will be kind of ugly. But it will work. I would use about five or more buckets distributed under the canopy, about three or 4 feet apart. The more buckets, the better.
The buckets are not made with UV treated plastic so you should paint the buckets or cover them so sunlight does not destroy them.
Make the holes small. Five gallon buckets should run out of water in 30 minutes to one hour. The hole will eventually become plugged so you must clean it periodically. Use clean water a clean bucket and make sure you put a lid on top.
Place the buckets on top of the soil or slightly buried. You don’t want to bury the buckets totally in the soil if the water is emptying from the bucket at the bottom. Most of the roots that take up water will be within the top 12 to 18 inches of the soil. If the bucket empties beneath this zone, the water will be released deep and not water the roots very well.
In urban desert landscapes, trees should develop two types of roots; roots that anchor the plant and keep it from blowing over and roots that take up water and nutrients quickly.
If trees planted in the desert are irrigated deeply, they will develop deep roots which will help anchor the plant in the soil. If they are not watered deeply but only receive shallow irrigations, they will not develop these deep roots.
You can also help the tree get additional water by planting other shrubs under its canopy and overwatering them slightly to provide additional water for the tree. Surface mulch helps conserve water and encourages deeper rooting, particularly wood mulch.

When and How to Prune Mock Orange

Q. I would like to cut back my dwarf mock orange. When can I do it and how much can I cut back without harming the plants? I am hoping to make them healthier. The back plant gets less sun.
Pruning too deep on the outside of mock orange can result in "holes" showing dead wood.

Mock orange pruned as a hedge
A. This is the mock orange of the desert Southwest, not the mock orange of northern climates. The common name of mock orange pertains to a couple of different plants.You won't be able to cut them back very much because the leaves are only on the outside couple of inches of the canopy. Once you cut beyond this layer, it's just a bunch of twigs and sticks. These twigs and sticks are alive and will produce new growth but it would be very unsightly until it grows back.
These plants grow very slowly so they will not come back quickly. If you decide to cut them back I wouldn't do it until late next spring when plant starts growing again and there is less time to look at a bunch of twigs and stems.
You can cut them back in late spring and open up the plant and you will see new growth coming from stems and branches that receive full sunlight. It might take a couple of months for them to start to fill in again. They are that slow.
Regarding the browning of the leaves, If you are going to cut them back I would pull back the rock from around them and put down some compost and wood mulch. They will do better in an amended soil.
I would then increase the irrigation so that it wets that area more and fertilize them with a tree and shrub fertilizer just after you prune them back.

Causes for Yellowing of Mock Orange

Q. Can you tell what is happening to my mock orange shrub?  They are 3 to 4 years old and getting enough water. They were planted in topsoil used in other locations with good results. They are the fourth different plant I tried to grow in this area without good results. The leaves are turning brown starting at the tips.
Readers mock orange

A. From your picture the leaves scorching like that could be not enough water applied or not applied frequently enough or even too frequently; high intensity sunlight and intense heat from surfaces radiating heat back to the plant; using a poor soil amendment at planting; lack of fertilizer or a lack of an iron fertilizer because the leaves are yellowing.
Mock orange, not dwarf, in good condition
These problems can be working alone or in combination with each other. If just one of these problems is present, it can affect the overall ability of the plant to combat extreme desert conditions such as high temperatures, low humidity and poor soils.
Mockorange is not a desert plant to begin with so we have to put more resources into keeping it look good. It’s one of those plants that does well if it is in the right location with the right type of soil amendments and irrigation.
Address the potential water issue first. I would flood the areas with a hose once a week in addition to your normal waterings. Make sure you are not watering daily but every 2 or 3 days right now.
Add good quality compost to the area. This can be on top of any mulch you have and water it in. Fertilize with a good quality fertilizer such as Peters, Miracle Gro or Osmocote. Add soil iron in the form of iron chelate, use only EDDHA iron chelate if applying it to the soil.

Water thoroughly giving the plant roots a chance to breathe and the soil to drain between flooding. Look for improvement to the plant the following spring (February to May). It is too late in the season now to see much improvement in growth.

Monday, October 13, 2014

Pruning Flowering Shrubs at the Correct Time

Q. When is the right time to trim back the Desert Princess flower and Purple Sage bushes and also how far down?

A. I don't know a plant called the Desert Princess flower. If you can send me a picture maybe I will know it. I also do not know a plant with the common name of Purple Sage. I'm wondering if this is Texas Sage or Texas Ranger which is not a true Sage.
Texas Ranger in Bloom. Prune this plant after it finishes blooming this fall

            The general rule for pruning flowering woody plants is to cut them back after they finish flowering. So if a plant normally flowers during the summer and fall months then we would prune it back in the winter. If a plant normally flowers in the early spring, then we cut it back in late spring or early summer when it has finished flowering.

When plants like Texas Ranger get woody or leggy, remove one or two of the largest stems from the base. This is called gradual rejuvenation pruning.
            If these are small flowering woody plants then we could cut them back to within a couple of inches of the soil. If these are larger woody plants then we remove the oldest or most woody stems deep inside the canopy.

When pruning in this way, it is customary to remove no more than about one third of the total plant in a single pruning. If the shrub is still unsightly or overgrown, the following year we again remove one third of the shrub. In this way the shrub is in a constant state of renewal with new growth coming from the bottom and older, larger growth being selectively removed.

Rose Leaves Turning a Bright Yellow and Wimpy

Q. My vining roses have bright yellow and wimpy leaves. Am I over watering? Under watering? I have fertilized, added sulfur and iron too. 

Readers rose vine
A. This subject of whether a plant is over watered or underwatered is difficult to answer remotely. From your description, it sounds possible you are overwatering but probably not under watering.
Why don’t I think you are under watering? If you are under watering I would expect to see more leaf scorch and dieback on the leaves. Yellowing of the leaves of any kind is called “chlorosis” and can come from a number of sources including overwatering.
When yellowing or chlorosis is due to a lack of available iron then we will call it iron chlorosis. Chlorosis or yellowing due to a lack of available iron usually makes the leaves yellow with green veins. When iron is severely lacking, the leaf may be entirely yellow and scorched, but these are extreme cases.
Typical iron chlorosis with green veins on peach
Surround your roses with wood mulch, not rock mulch. If these plants have rock mulch surrounding them, rake it back a couple of feet and apply a couple of inches of compost first followed by some wood mulch. In this particular case do not use decorative bark mulch until the plants begin to recover. Decorative bark looks nice but it doesn’t do much for the soil.
Apply an iron fertilizer in the form of an iron chelate before you cover the soil with mulch. The chelate should be in the form of EDDHA which should be listed in the ingredients. The type of iron you add is very important. Mix the iron chelate in a bucket of water and pour it all over the soil above the roots or sprinkle it on dry and water it in. Don’t leave it on the surface because it is sensitive to sunlight.
Iron chelate with EDDHA on the label
Also, fertilize with a rose fertilizer or a fertilizer that has been formulated for flowering trees or shrubs. Avoid watering daily and try to give your woody plants a couple of days rest from any additional water before you irrigate again. Having wood mulch on the surface will help.
Specialty fertilizer formulated for roses
Always keep wood mulch a few inches away from the trunk of any plant to prevent stem diseases such as collar rot from occurring.

Older Star Jasmine No Longer Blooms

Q. We have a gorgeous, shiny dark green star jasmine, over 25 years old. About 5 years ago, it stopped blooming and nothing we've done has helped. Please help.

A. When that happens to older plants of mine I usually cut it back pretty hard and try to get it to regrow again, getting rid of some of the older wood.
Star Jasmine no longer flowering
Sometimes by cutting up plant back it restores some juvenility and it responds by growing more vigorously and flowering. I would also give it a good shot of fertilizer if you haven't already and soak the roots with a hose a few times, a few days apart.
Star Jasmine
It is late in the year to be pushing new growth so you could try this in early spring instead of now. However, star Jasmine is pretty hardy in our area so fertilizing it now should not affect its cold hardiness. It will respond with a flush of new growth next spring without any applied fertilizer.

This is a technique of applying a fertilizer late in the fall to get a spring response is called late fall fertilization. Fertilizer is applied in November before the leaves drop. Nutrients are stored in plants if they are not used up. If you combine late fall fertilization and cutting it back, cut it back first and then fertilize, not the reverse. Otherwise you would be cutting off parts of the plant that has stored nutrients. Let me know if this works for you.

Plant Onion Seed Now

Q. I would like to grow both yellow and red onions. When is the best time to plant them?

A. Onions for bulbs or green onions can be planted from seed mid-September through November in our latitude and elevation. Onions produced from sets or transplants should be started in March. They can be grown in a garden spot or 5 gallon containers. Onion sets, which are small onion bulbs, are
Contessa onion
easier to plant than transplants and usually have a higher success rate for most home gardeners.
Let’s focus on fall planting using onion seed. Growing onion from seed to produce green onions or transplants does not require very much space. Seeds can be spaced close together so I broadcast the seed, or sprinkle them, in the area where I want them to grow. The seed can be as close as ½ inch apart and even closer for green or bunching onions or even transplants.
For green onions just about any onion will do so shop for inexpensive seed. If you are growing transplants from seed then be more careful in your selection. I prefer sweet or specialty onions for transplants that I am growing into bulbs.
Big Daddy Onion
Las Vegas is in a transition zone so we can grow short day, long day and intermediate day varieties. These include the northern varieties like Walla Walla or southern varieties such as Vidalia. They just mature at different times. Varieties such as Candy, Big Daddy, Vidalia, Walla Walla, Yellow Granex, Bermuda, Texas Super Sweet, Contessa, Sterling, Red Marble and specialty onions like Cipollini, and Red Longa always do well in our climate and latitude.
Red candy apple Onion
Before planting the seed prepare the soil to a depth of 12 inches. Sandy soils that drain well are the best. We are not yet focusing on growing the bulb so any high nitrogen fertilizer will work well. You won’t need to fertilize them until after the seed is germinated. When you’re done mixing all the compost into the soil, make sure the soil is not “fluffy” so pack, roll or compress the soil lightly to make a firm seed bed.
Onions for transplanting, green onions or bunching onions grow well in containers or in blocks. They do not need to be planted in rows at this time. Carefully scatter the seed on top of the soil and cover the seed with about ¼ inch of topdressing or lightly rake the seed into the soil and add a light surface mulch.
Red Tropea Longa
Water the top dressed are mulched area twice a day until you see germination. Fertilize them after you see them begin to emerge. You can lightly broadcast a high nitrogen fertilizer on top of the mulch or topdressing and water it in. When you see germination reduce your watering to once a day. If onions are too close together, harvest and use some of them in a salad or stirfry to give them some space. As temperatures cool down and the plants get larger you will be able to water every other day and even every third day as it enters the winter. You will get larger transplants if you fertilize a second time with a nitrogen fertilizer about one month after the first one. Leave them in the soil all winter long. Dig up transplants in March or continue to use them as green onions.

Sunday, September 28, 2014

San Pedro Cactus Requires Different Care Than Other Cacti

Q. I follow your column regularly in the LV RJ, but I have not seen an answer to this question: what would make my San Pedro Cactus lose its color? It is becoming pale, please see attached photo.
San Pedro cactus of the reader
A. Before I opened your picture I thought it was going to be a lot worse. This is not too bad. I have seen this cactus in much worse condition in Las Vegas.
Not all cacti are the same and cannot be treated the same. The San Pedro cactus, coming from the mountains of South America where the soils are a lot richer and there's much more water, needs different care than cacti native to the Mojave Desert.
This particular cactus will do much better if the soil is well prepared at the time of planting, much like you would prepare the soil for landscape trees and shrubs that are non-desert.
Also irrigating them is different. They have to be watered much more often than cacti native to the Mojave, Sonoran or Chihuahuan deserts.
It will also do better if protected from late afternoon sun. It likes to have lots of direct sunlight but it prefers it during the morning and early afternoon hours.
If you don't keep up with your watering with San Pedro it will begin to yellow or bleach out, scorch around the edges, bleach out and die back. This means the soil that you're using must drain extremely well or you will kill it by not having adequate drainage.

Consider moving it, replanting it with the soil that is Sandy and gravelly and amended with compost. Make sure the area has deep soils that drains easily. Give it is much sun as possible but try to avoid direct sunlight after 2 PM. Water it frequently when temperatures are above 100° F.

Radishes Should Be Planted When Temperatures Begin to Cool

Q. I planted radish seeds in 8" deep planters using miracle grow potting soil . After approx. 10 days they grew up to approx. 3" developing 2 leaves and started falling over. They do not mature. The type of radish seed is Cherry Belle from Ferry Morse.  I've planted two different times and get the same results. What am I doing wrong?

A. It is usually considered too hot right now, with daytime temperatures still hundred degrees F, to plant radishes. They do much better when the temperatures begin to cool.
I would start planting them no earlier than about mid-October and you should be able to plant them throughout the winter in successive plantings up until about May when it gets too hot. Cherry Belle is an excellent radish and will do well hereHere are just a few of the many varieties we have grown in Las Vegas.
Chinese red meat radish
Radishes growing with irrigation from drip tape and straw mulch applied
French breakfast radish
White icicle radish
I have tried dozens of different radish varieties and not found a radish yet that does not like our climate. However radishes grown during the cooler months are not as spicy but sweeter than those grown in the hotter months.
Hold off for another month and try replanting the seed. The potting soil may also be a problem. Seeds like firm seed beds, not soft seed beds. I would take your soil amendments and mix it with existing native soil or good-quality sand and tried again.
After you work in your compost and prepare the area for planting, your shoes should not sink into the soil more than about 1/2 inch for a good seed bed. Radishes also grow well in containers.
Containers do not have to be terribly deep. 12 inch deep containers are adequate for radishes and allow the soil to drain and not become a problem for the plants.
So remember to use a soil mixture with compost or other soil amendment and make sure the seed that the seed bed is firm and not soft and fluffy. Watering twice a day until you see the seeds germinate should be enough. After they germinate water only once a day. I hope this helps.