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.
A: It is not uncommon for early apricots to set fruit first, followed shortly thereafter by leaf and shoot growth. 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.
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.
If your 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 that 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.
Secondly, spread a 3- to 4-inch layer of wood chips on the surface of the soil around the tree and out to at least the edge of its canopy. Keep wood chips away from the tree trunk a few inches to avoid causing a disease called collar rot. This mulch layer helps keep moisture in the soil and enriches it. You should see the tree explode with new leaf growth in about a week or two.
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?
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, the plants will probably die. It’s hard to harvest enough roots when moving desert plants to a new location.
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 it is watered less often and the soil growing it 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 too 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.
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.
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.
Q: I am curious if my goldenball leadtree 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 goldenball leadtrees are like that. They are slow to flower, but when they do start, it is perpetual every year.
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 it’s ready.
Start building a tree’s structure early in its life. You can do this with a couple of well-placed pruning cuts so the scaffold limbs originate at the right height and location.
Goldenball leadtree is a very hardy small desert tree native to the Chihuahuan desert in areas of south Texas and northern Chihuahua state, 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.
Q: I have two bay laurel trees planted in a narrow bed behind my swimming pool. They were planted there for about seven years, and in the past 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.
A: It sounds like an irrigation or soil issue if it’s affecting all the leaves on the tree. 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. That will result in more water applied to the area.
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, more water is provided during the same number of minutes. Don’t increase the number of minutes on the controller. That results in all of the irrigated plants getting more water.
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.
Whenever you look at old leaves, it tells you about its past problems. The new growth tells you how the tree is doing at that time. 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 wood chips.
Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.