In an attempt to find a drought-tolerant ground cover for his Irvine homeowners’ association landscape, Jim Harrison introduced kurapia in selected areas this summer. Harrison wrote that it was “planted in July, filled in nicely in August, and survived well in September heat.”
He found it to be a “great substitute for brown grass problems. We are expanding the use in mixed shade/sun areas; it uses the same sprinkler time as low-water plants watered from the same valve.” He did mention that “some dog owners are concerned about the increase of bees” since bees do sting dogs, as you may know. I would suggest monthly mowing of the kurapia since that generally prevents kurapia flower development. The kurapia had been installed in sod-like strips.
I received another email from Irvine, this one detailing the history of a Japanese maple that was planted in an enormous ceramic pot five years ago. It is doing quite well in an area where it is exposed to sun in the early morning and shade throughout the afternoon. However, it now has an unkempt look and so the question arises as to whether it should be treated to an artistic pruning or lacing in the manner of well-trimmed trees growing in the ground. A desire is also expressed for a “graceful, understated maple” similar to those at the Huntington Gardens in San Marino.
Upon seeing a photo of the tree, I noticed that shoot terminals on the ends of its branches appeared to be dead. This is commonly seen on trees in a root-bound condition, meaning that its roots are circling the interior of the container. After five years in the same container, even a slow-growing tree like a Japanese maple will probably have such roots and so it would be advisable to remove the tree from its container, cut back a third of the roots in symmetrical fashion and, while you’re at it, replace the existing soil with a fresh batch. Of course, a tree growing in a container can be pruned for aesthetic reasons, as long as it is done sparingly and with great restraint.
I also noticed that there appeared to be some ferns growing out of the container. It is never a good idea to plant anything in a container where a tree or other woody plant is growing. Even where a tree is growing in the ground, it is best not to plant anything directly underneath it unless the undergrowth has shallow roots and requires a bare minimum of irrigation.
I received a letter from someone with a large jacaranda tree that is lifting the edge of their driveway. They have received a suggestion to cut away roots from the tree leading to the driveway and prune the tree as a solution to the problem. They also asked if I could supply the name of a competent arborist who could do this work.
Master Gardener: Your plant and gardening questions answered
Why you can plant these summer vegetables now for a winter crop
Master Gardener: How to keep rodents and other critters out of the garden
The benefits of planting drought-resistant groundcover in your garden
Plant, relocate and fertilize: What to do in the garden this week
I would be reluctant to recommend removing roots of a large tree out of concern that doing so could undermine the tree’s support. Still, I have known of cases where roots that lifted sidewalks or driveways have been pruned without any adverse consequences. The point is that when you hire an arborist for any purpose, you want to make sure that he is licensed and insured. Still, the liability of contractors in California extends for only one year, so you would also want to keep this in mind. In addition, it is likely that the tree roots that would be trimmed will eventually grow back and lift the driveway once again, so you may want to consider removal of the tree as another option.
As for finding a competent arborist, you will want to contact the ISA (International Society of Arborists) since it is the most reputable body for licensing arborists in California or anywhere else. Access these arborists at no charge at ISA-arbor.com. When you get there, click “Find an Arborist” and follow instructions to locate arborists in your area.
Joseph Ortega, whom I call the “wizard of Wilmington” due to his unfailingly effective and often original gardening practices wrote as follows: “I have had great success growing chili peppers with a 5-10-10 fertilizer by Lilly Miller. It is a slow-release product that is available at most lawnmower shops. It works well for me on all vegetables and fruit trees, as well as on flowering plants and bulbs. As for those chili peppers, my ghost peppers, Carolina Reapers, Chile de Arbols and New Mexico chile plants normally last me two to three years and produce nicely every year. Worm castings take care of the micronutrients and minerals and help keep away pests. The chili plants get midmorning sun on the west side of a wall. The ground is mulched with shredded bark and is watered one to two times a week.”
In the 100-degree temperatures we have recently experienced, it is recommended to place shade cloth over vegetables growing in full sun whose fruit would otherwise burn (in the case of tomatoes) or whose foliage may wilt (in the case of peppers). You can find 6′ x 15′ pieces of shade cloth at home improvement centers, nurseries, or order them from online sources. Where temperatures are less than 100 degrees, 30% shade cloth (meaning 30% of sunlight is blocked) is sufficient, but where temperatures soar over a 100 degrees, 60% shade cloth is recommended. Drape the shade cloth over your plants at 10 a.m. in the morning and remove it at dusk. This information was gleaned from the website at gregalder.com, a site I highly recommend for vegetable and fruit growers in Southern California.
California native of the week: We do not normally associate California natives with sweet fruit, but golden currant (Ribes aureum) defies this categorization. Moreover, golden currant offers not only heavy crops of tantalizing fruit but appealing visual and olfactory delights as well. Dense clusters of yellow flowers come in the spring with a fragrance that resembles that of cloves or vanilla, depending on whom you ask. These are followed by fruit that ripens to gold, red, or black. Three-lobed foliage imparts a sense of softness and ultimately turns red before dropping in the fall. Golden currant will grow in full sun along the coast but demands partial shade inland. Golden currant plants grow into large shrubs six feet tall and six feet wide. Where soil is to their liking, the seeds they drop will germinate so you will have golden currant babies to give to your friends. If anyone is aware of other California natives with sweet fruit, please let me know about them.
Please send questions, comments, and photos to firstname.lastname@example.org.