Bay Laurel with Scorched Leaves

Q. I have two bay laurel trees planted in a narrow bed behind my swimming pool. They were planted there for about 7 years, and in the last couple of years, the leaves have developed brown borders and spots. There doesn’t seem to be excessive leaf drop, but the leaves don’t look healthy to me.

Bay Laurel tree will be healthiest surrounded by woodchip mulch

A. Sounds like an irrigation or soil issue if it’s affecting all the leaves on the tree. 

Irrigation or Soil Problem

I would guess it’s drought (not enough water) or the soil was kept too wet for a long period of time. Both give brown borders (scorch) to the leaves. My guess is that the trees need water applied to a larger area underneath their canopy. This will result in more water applied to that area.

            Judging from the pictures you sent, this is not a true disease problem.

Bay Laurel Planted from 24 Inch Box

Add More Emitters for More Water

            As trees get older and larger, their water requirement increases and the number of emitters placed under the canopy also must increase. By increasing the number of emitters under the tree, or increasing the size of emitters or both, provides more water during the same number of minutes. Don’t just increase the number of minutes on the controller. That results in all the irrigated plants getting more water.

Bay Laurel can be pruned

Don't Water Too Often

            A word of caution. If the soil is overly wet for weeks at a time, then it can cause the same look. When the soil is overly wet it causes root rot and the tree looks like it is not getting enough water (it’s not getting enough water because the roots rotted!).

Leaves Tell You the Past

            Whenever you look at old leaves, it tells you about its past problems. The new growth tells you how the tree is doing NOW! If you agree with me that it is probably a lack of water, flood the area under the trees with a sprinkler and look at the new growth in a couple of weeks. If the new growth looks strong, add more drip emitters under the tree canopies. After adding the emitters, refresh the top of the soil with a 3-inch layer of woodchips.

Golden Lead Ball Flower Production

Q. I bought the trees and soils you recommended. I am curious if my Golden Lead Ball tree will produce "balls" this first year? Can you point out where to look on the branch, or is it obvious when it happens?

A. Most likely it will not flower or “ball” for about six years, when it gets old enough. Many native desert trees like Golden Ball Lead Tree are like that. They are slow to flower but when they do start, it is perpetual every year.

Yellow or Gold Balls Are Flowers

            These “balls” are its flowers. All flowers are considered “modified leaves”. They always emerge from new growth and from the same places where leaves are formed. In some plants, the plant does not know if its new growth will become leaves or flowers until it figures out its status for that growing season. But these “balls” emerge from new leafy growth when its ready.

            Early in its life is the time to start building a tree’s structure. You can do this with a couple of well-placed pruning cuts so the scaffold limbs originate at the right height and location.

            Golden BallLead Tree is a very hardy small desert tree native to the Chihuahuan desert inareas of south Texas and northern Chihuahua (Mexico). Water it twice a week to about 18 inches deep to get them established. New growth is your signal that the tree is establishing. If you want to “push” its growth, then water deep once a week during the summer. If you want to slow it down, don’t water as often.

            Established desert trees signal they need water when their leaf canopy starts to thin out. Water them 18 inches from the trunk to the edge of their canopy as they get bigger. Give them enough water to wet the roots to 18 inches deep. Watering them along with other trees in the landscape works for the first couple of years but they will grow very fast like that.

Growing Desert Marigold in the Landscape

Q. I want to grow some desert flowering plants like Desert Marigold in my landscape. In the past, when I attempted to transplant them from seedlings, they did not make it. Is there a technique to transplanting or am I better off planting the seeds directly into the soil?

Opuntia (nopal) cactus flower

A. Once established, desert plants are difficult to move.  If you sow seed into the landscape, get them to grow and then try to move them to a new location, then that is probably why the died. It’s hard to harvest enough roots when moving desert plants to a new location.

Start Wildflowers from Seed in Containers

            You are better off starting plants from seed in containers and then moving them into the landscape once they have solid growth. Kind of the same as starting tomato or basil transplants from seed but without watering as often. If you do move them to a new location, take lots of roots with the plant and cut the top back to reduce its need for water!

            Desert marigold is native to the Mojave Desert and can be grown from seed easily provided they are watered less often and the soil growing them doesn’t hold water. Wet or damp conditions kill new plants or the germinating seed. Spread twice as many seeds as you need on top of a well-draining, coarse gravelly or sandy soil in the spring and cover the seed lightly with a thin sheet of sand. Cactus soil works well.

            Use small plastic or peat containers to start them but 8-ounce paper cups work as well provided you make sure they drain water easily. Don’t use rocks in the bottom of the cup but make sure there are holes that allow water to easily drain.

Starting Wildflowers Seed in the Landscape

            In the landscape, rake the seed lightly into the soil with a garden rake. Lightly apply a sand layer. After you’re done, water with a spray nozzle so the seed gets wet and the sandy sheet tucks them in. Then fight the urge to sprinkle them daily, or even every other day, until you see growth appear.

Warning about Collecting Seed

            Remember, don’t collect seed or plants from public lands. Secondly, get permission from landowners in writing when collecting seed or plants from privately owned land.

Small Fruit Trees are Best With Dwarfing Rootstocks

Q. I watched your pruning videos on YouTube and learned a lot! Is it possible to reduce the size of a standard sized apple tree to a dwarf size this way?

"Dogleg" where scion was grafted to the rootstock about a year earlier

A. Probably not. Standard sized apple trees may grow to 35 or 40 feet in height. You might be able to keep a standard sized tree under 20 feet tall (maybe 15 feet if you’re really aggressive) through pruning but I don’t think you will get it to eight feet tall which is what I aim for in pruning semi dwarf trees for backyards. I call the size of these fruit trees “ladder less”. The standard sized apple tree is just too vigorous for pruning to short heights.

Dwarfing Rootstocks

            Standard sized apple trees normally grow 30 to 40 feet tall. Buying these trees on semi dwarfing rootstocks will keep them smaller than this but it depends on which semi dwarfing rootstock the tree has been grafted onto. I have found that the M111 semi-dwarfing apple rootstock is probably the best semi-dwarfing apple rootstock for backyards in our climate.

            Using this semi-dwarfing rootstock, I have been able to keep Pink Lady and Mutsu apples, for instance, pruned at eight feet through appropriate pruning methods. Apple trees grafted onto M111 rootstock will normally get to 80% of its mature height if left unpruned.

Nursery Tags

          

Nursery tags on a fruit tree from Dave Wilson Nursery showing the rootstock (other color) and the scion (white tag)

Nursery tags from Dave Wilson Nursery on a fruit tree of the rootstock and the scionrseries sell fruit trees with a tag that calls the tree a “semi dwarf” because most people don’t know the different kinds of semi dwarfing rootstocks. In our area an apple that is labeled as semi dwarf is most likely grafted on to M111 rootstock. There are online stores for fruit trees, such as Grow Organic and Bay Laurel, that specify the rootstock used and the most common semi-dwarfing rootstock available on apples for backyards in the Western US is M111.

Early Apricot Produce Fruit First

Q. I have a 9-year old apricot tree that produced a bumper crop of delicious apricots each year.  However, this year there is an abundance of fruit set, but not many leaves. Unless the number of leaves increases significantly, I doubt if all the fruit will mature. I fertilized this apricot tree the last week of January using 10-15-15 fertilizer spikes as I do every year.

Early apricots produce fruit first

A. It is not uncommon for early apricots to set fruit first, followed shortly thereafter by leaf and shoot growth. 

Apricot Flower Production Is Early

The tree “invests” in its fruit production early by shoving stored food reserves into fruit production. You’re right. At some point the tree will not “invest” anymore and it will expect the leaves to start contributing. But that shouldn’t be for a few months.

            Later in the year the apricot tree recovers its stored food investment plus more because of the new leaf growth combined with the presence of fertilizer in the soil. Fertilizer is applied just before growth starts happening. So, in mid-to-late January (very early Spring) is a good time to apply fertilizer.

Look at Leaf Color

            Over the next couple of weeks observe the new growth. Look at the color of the leaves and the strength of growth. Dark green leaves mean the nitrogen fertilizer is inside the leaves and ready to push new growth. If we experienced cool weather earlier, then growth is slow until it gets warmer and then the tree should grow like gangbusters!

Nitrogen Produces Leaves and Stems

            If you’re established tree is not putting on some new growth by April 1, apply a high nitrogen fertilizer around the tree such as 21-0-0 or a rich compost which does basically the same thing. Spread one bag of rich compost, or about 3 pounds of 21-0-0, in a circle around the tree 18 to 24 inches from the trunk. Water it a few inches deep into the soil by hand or sprinkler. It’s important not to apply fertilizer or rich compost too close to the trunk or it could cause the fruit to drop or damage the tree.

Mulch Conserves Water

            Secondly, spread a 3 to 4-inch layer of woodchips on the surface of the soil around the tree and out to at least the edge of its canopy. Keep woodchips away from the tree trunk a few inches to avoid inciting a disease called collar rot. This mulch layer helps keep moisture in the soil and enriches it as well. You should see the tree explode with new leaf growth in about a week or two.