Ask the Garden Guru
Garden Guru Topics
Crepe myrtle is no longer flowering
Dear Garden Guru,
My crepe myrtle is no longer flowering. The tree is robust, healthy good structure, but a few years back the flowering tapered off, this year no flowers. Any thoughts?
Karen in San Rafael
Hi Karen,
Crepe Myrtles flower on new wood. If the tree is not pruned regularly in the dormant season (winter), new flower wood is not generated and the tree eventually stops flowering. You do not need to prune drastically; just shearing back the shoot tips is sufficient.
Need recommendation for a flowering tree that offers privacy
Dear Garden Guru,
We searching for a small tree recommendation. We are looking for a tree (or two) to plant between our patio and our fence that will afford some privacy from passersby on the sidewalk but is still small enough fullgrown to never interfere with overhead powerlines. Of course, the ideal tree would either flower in the spring or having pretty fall foliage, but any advice will do!
Anna in South San Francisco
Hi Anna,
If you enjoy flowers, these trees bloom in spring- flowering cherry, flowering plum, and crabapple. They also lose their leaves in the winter.
These trees are evergreen – Dodonaea, also known as Hopseed, has rich purple foliage. Purchase it as a ‘standard” (trunk with a head as opposed to a shrub). Arbutus Marina has beautiful bark and pendulous white flowers in spring. Magnolia Little Gem is a small sized tree with fragrant, summer blooms.
Planting fruit trees on a hillside
Dear Garden Guru,
We have a plot of land that is on a hill. I would like to plant some fruit bearing trees. Our hill faces West and gets a lot of sun. What sort of fruit bearing trees would you recommend and do you see any problems with planting these kind of trees on a hill that slopes 20 degrees or more? We may have to build some sort of retaining wall to make it happen, but I wanted to see what your thoughts are in terms of planting these type of trees.
Bruce in San Francisco
Hi Bruce,
I see no problem with planting fruit trees on a slope. Most every fruit tree prefers good drainage which a slope will provide. You would do well with apple, pear and plum trees. You will most likely need to do some excavation to form recesses that the trees can be planted in and take into account how you will reach future harvests.
Growing plums by the beach?
Dear Garden Guru,
I live on 42nd ave right near the beach in the Sunset. I really want a good, fruiting plum tree but there are so many to choose from. Is there a particular cultivar that works the best in my microclimate? If there is no such thing, then is there another fruit tree that does well out here?
Anja in San Francisco
Hi Anja,
We carry the Santa Rosa plum which is self fertile and requires very little chilling. This is the best producer for your area. They are due to arrive at our store by the Zoo in January.
Protecting a Japanese maple
Dear Garden Guru,
I have Japanese Maple planted in the front yard, in an open area getting either too much wind/sun. How do I protect the tree and will it die before winter sets in?
Ruby in San Bruno
Hi Ruby,
Your Japanese maple may have burned from those 2 or 3 days of intense heat we had. It should be fine. It is important to be sure that the plants are well watered, especially if newly planted. The leaves will begin to fall off shortly, probably sooner than normal if they scorched. New leaves will resprout in the spring. To prevent further wind damage, spray the tree with Cloud Cover or Wilt Proof after watering. The coating will prevent moisture loss in the leaves.
Princess Tree needs help
Dear Garden Guru,
Help. My Princess tree is doing very poorly. It is on my terrace with an easterly and southern exposure. The leaves, what are left of them are curled, yellow or spotted. Small birds have been landing on the branches and pecking at them. I have tried various organic sprays to no avail and at the same time need to be mindful of hummingbirds.
Judith in San Francisco
Hi Judith,
It sounds like a couple things are going on. First, the birds on the branches are obviously finding some insect pest to eat, possibly scale or thrips. What have you been spraying the plant for? Insects? Fungus? The Greenlight Rose Defense can be used to combat aphids and scale. Spinosad, a bacteria based insecticide, will work on thrips, aphids and caterpillars. Both of these sprays will not harm birds. The spots on the leaves may indicate thrips damage if they are small and black. Another problem may be that the Princess flower was damaged during the cold weather. Cold damage would be loss of leaves, twig dieback and yellowing. It would be best to take a sample into the Sloat nearest you for a better diagnosis.
Planting apples & nectarines
Dear Garden Guru,
I have a large sloped yard and would like to plant more fruit trees. I am fond of Fuji apples and nectarines. My yard is wet in winter and damp through early spring. Sunlight is plentiful in summer and fall. Any chance these fruits will grow here?
Dave in South San Francisco
Hi Dave,
You will have more success with the Fuji apple. The nectarine requires more winter chilling than you may get in South San Francisco. Should you want to try, I recommend the Independence variety. The wet winter soil is not an issue as it dries out at the appropriate time.
Rescuing Lime Tree In Distress
Dear Garden Guru,
My dwarf lime tree has been losing leaves (now almost bare) and its branches are turning brown...I know they are supposed to be green. I've had the tree for 4 years now and I water and fertilize regularly. Please help.
Danny in San Francisco
Hi Danny,
We had colder than normal temperatures this winter in San Francisco. There was even a period of overnight temperatures below 30 degrees. I suspect that your lime tree is showing the extent of its cold damage. The extent of the damage shows up once the temperatures warm up and the season changes. You will probably lose many of the smaller branches. Everything that has died should turn brown by the month’s end. At this time, prune back to healthy wood to stimulate regrowth. Since all the leaves have fallen, do not continue to water regularly or feed. Feeding a distressed plant does more harm than good. You also do not want the soil to stay constantly wet.
Curious if we have your favorite plant or product in stock? Call one of our locations directly and we'll be happy to check.