Q. I notice my potted plumeria are starting to drop leaves at an alarming rate now that summer has passed. Most are exposed to evening coolness, and I wonder if it is better to move them from their current locations to under my patio cover now that the night temperatures are dropping. They will receive little light during the day, but more protection from evening weather. What do you advise?
– Harry Moak, Simi Valley
A. I would definitely move your plumeria under your patio cover because this will offer you a significant measure of protection should we experience a bad freeze, which seems to visit us once every 10 years or so. I once had a 2-year-old plumeria that was killed by one of those occasional freezes. Had it been under my porch roof, I believe it would have survived. Any sort of overhang, from roof to tree branches, increases temperatures below. Without an overhang, heat that accumulates on the ground during the day is lost into the atmosphere at night. An overhang traps the heat so that it envelops plants beneath it on a frosty night.
Once a plumeria reaches around 5feet tall and has developed its signature branching structure, it may be damaged by a freeze but should survive. Plumeria, with highly fragrant, pinwheel-shaped white, yellow, pink, red or multi-toned flowers, should be treated like a cactus, more or less. It does not need to be watered more than once a week in summer except when temperatures exceed 90 degrees, and should pass through the winter, when it is dormant, with soil kept bone dry or nearly so. The Valley is fortunate to have a local nursery, in Northridge, that grows more than 100 plumeria varieties. Visits are by appointment only. Call 818-970-2483 or go to www.islandplumeria.com for more information.
Q. In the last month, I noticed that the leaves on my basil plant are faded, split or turning brown on the end. Some leaves fall off even though they’re green, and a little shoot suddenly turned brown at the top, lost its leaves and progressively went brown to the soil, and I yanked it out easily. I thought I was overwatering it but am watering it less than before. The soil is dark, seems damp but if I don’t water it almost daily, I’ll find it drooping over. I’m also getting little shiny areas on some of the leaves. I have it inside in a sunny spot. I’m tempted to replant it in a bigger pot. What am I doing wrong? It’s still growing leaves but it sure doesn’t look healthy.
– Coleen Ota, West Los Angeles
A. The common basil (Ocimum basilicum) you are growing is an annual, which means you get a single good growing season from it (spring to summer and perhaps into fall) and then it dies. It might just be going through its natural life cycle. To be truly happy, basil requires excellent light and moist, but fast-draining soil. Basil is the odd man out when it comes to growing herbs.
Other culinary standbys, such as oregano, thyme, sage and rosemary, are much less water-needy – when grown in pots or in the garden – than basil. Much of the basil we consume in Los Angeles comes from Baja California, which tells you something about its ideal growing conditions. It prefers a more tropical climate than Los Angeles, favoring moisture-laden air over damp soil.
Do not transplant any struggling plant, including basil, into a larger pot since the extra water required to moisten the soil could exacerbate soil fungus problems. The fact that you could easily pull a rooted shoot out of the soil points to a fungus issue.
You should also make sure your potting soil is not too water retentive. Store-bought potting soil is really designed for indoor plants. Regular garden plants in general, and herbs in particular, need a sandier soil to grow their best. If you mix store-bought potting soil with washed, construction grade sand, you will create a soil mix better suited to basil.
Keep in mind that basil needs lots of sunlight to grow well. Just because basil is a tropical plant – and requires more water than tougher Mediterranean herbs such as thyme, rosemary and oregano – does not mean it will grow well in low light the way some tropicals are capable of doing.
Incidentally, cilantro is another annual herb you may want to try. In contrast to basil, it is very easy to grow. It needs little water and produces abundant seeds so that you can keep it in the garden from one year to the next without having to resupply with new plants. Scatter cilantro seeds (known as coriander) on the soil surface any time of the year, dust a thin layer of compost or potting soil over them, water occasionally, and you will soon have a respectable crop of cilantro for seasoning your guacamole dip.