Fertilizer should help leaves, blossoms

: I have a question regarding my Meyer lemon. Last year, during the spring the tree had many blossoms but dropped them all so thus I had no fruit. The leaves were yellowed. I believe this means it may be short on iron. What should I be doing right now to make sure I feed the tree what it needs and try to get a crop of lemons this year?

A: I would recommend that you apply a fruit tree fertilizer to the tree as soon as possible. Keep it away from the trunk but put it where the water normally irrigates the tree. Let the water move the fertilizer to the roots. Follow the directions on the label.

If you cannot find a fertilizer labeled for fruit trees, then use any fertilizer that is also suitable for roses or other blooming trees or shrubs.

The yellowing of new leaves but with the veins remaining green usually means an iron deficiency. If you can find an iron product containing iron in the form of EDDHA in the ingredients, then you would use this product for yellowing. Follow the label directions.

If the tree has not had any compost or organic amendment added to the soil, then add compost to the soil surrounding the tree, particularly near the source of water or irrigation. If the tree is in rock mulch or bare ground, then add surface wood mulch to a depth of at least 4 inches to the area beneath the tree and out to the edges of the branches. It is wise to keep the mulch away from the trunk on young trees in particular.

Water the area around the tree thoroughly with a hose or fill the basin around the tree with water two or three times or until the soil is thoroughly wet. This might be with a slow dripping hose. If the tree is about 6 to 8 feet tall, you should be adding around 20 to 30 gallons this way.

Be careful on how quickly you apply water to the tree or you may wash the applied fertilizer to a location away from the tree or against the trunk. Fertilizer washed too close to the trunk can damage the tree. If in doubt, use fertilizer stakes about 18 to 24 inches from the trunk near the water source.

This time of year you should water deeply once a week. Some time around May 1, or sooner if it gets hot, water twice a week with 20 to 30 gallons each time. This would be for trees about 6 to 7 feet tall and the same spread. Big trees will need more water than this. Smaller trees will require less.

Q: We have a Meyer lemon tree that has been in the ground about three years and we have gotten about six lemons from it. This winter it started with good growth and lots of new leaves and then I noticed that something was eating the leaves. I immediately thought of caterpillars because of the pattern on the damaged leaves. It has eaten the leaves entirely from several 3-foot limbs. I applied some Sevin insecticide but I am anxious to know what is eating my Meyer.

A: Citrus leaves can be quite tasty so there could be a number of things going on. Usually, with caterpillars the entire leaf or most of the leaf is gone. I have had reports of some caterpillar damage already this year. Most of these caterpillars were forming “tents” with their webbing so they were easy to spot and control. They can be controlled easily with an organic pesticide called Bt (sometimes marketed as Dipel or Thuricide) or a new product with spinosad in the ingredients. Never spray pesticides of any kind while the plant is in bloom.

Some caterpillars may leave the tough central vein behind but basically the leaf is gone. If the leaf has notches removed from the edges in irregular patterns, then this may indicate root weevils. They eat at night so you would not see them during the day. Snails or slugs also can cause leaf damage, but this is a longer shot in our climate and this time of year.

The caterpillars will be gone shortly so the problem would naturally disappear. But if the damage is due to root weevils, then this is a long-term problem that is difficult to control. If the problem is not excessive, you might be able to ignore it. If the problem is excessive, then you might have to apply insecticide to the leaves at dusk.

Q: I am having my front yard relandscaped this week and wish to include one well-performing, dwarf stone-fruit variety. My first choice would be an apricot, second a peach and third a plum. I definitely would prefer a dwarf variety. I found a little information on the Flora Gold apricot but I’m concerned that even it may grow larger than I’d prefer. Do you have any suggestions as to a well-performing variety of dwarf stone fruit?

A: The only dwarf fruit trees that we consistently use at the University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas with good fruit are the apples. They are fairly large trees to begin with so they are grafted onto what are called dwarfing rootstocks. Common dwarfing rootstocks are M106, M111, M7 and the like. Stone fruits like apricot we just keep pruned small, usually 6 to 7 feet tall and about the same in diameter.

There is some confusion in the nursery trade about dwarf stone fruits like apricot and peach. You can get genetic dwarf peach and nectarine but the so-called other “dwarf” stone fruits are probably not going to be actual dwarfs.

If you are really dead set on a dwarf fruit tree, then get a genetic dwarf peach or nectarine. Dwarf peach like Bonanza or Pix Zee will be OK. The fruit isn’t the best, but it will be dwarf as you wish. A good dwarf nectarine is one called Necta Zee. I am not sure if your local nursery will carry it or not.

If you are really focused on quality fruit, then I would pick your Flora Gold and just prune to keep it small. You also can buy fruit trees online and shipped in containers if you do not find the variety you would like here locally.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at morrisr@unce.unr.edu.