For the past three years, we have grown lemon cucumbers at our home in the Arden Park area of Sacramento. For two years, they were planted directly in the ground and this year in a large clay pot.
In all cases, they have started fine with lots of vines, blooms and eventually cucumbers. With no apparent warning, white, fuzzy spots appear on many of the leaves. Left untreated, the plant is soon dead.
Last year, we tried treating with fungicide, which seemed to work at first, but then the spots returned.
The fungicide is expensive and we would prefer to skip the chemicals. Is there something else we can do to avoid this problem?
Sharon Hale, Sacramento
The white fuzzy spots you describe sounds like fungus, according to UC Master Gardener Maureen Hefti.
Plants in the curcubit family including melons, squash and cucumbers are vulnerable to several fungi including fusarium, pythium, powdery mildew and white mold, to name a few.
It is impossible to accurately diagnose which fungus has infected your plants based on your description alone. Fortunately, the recommendations for preventing the fungus in the home garden are similar.
Prevention is the best control. When conditions are favorable and the host plant is right, fungus begins to grow and reproduce.
Plant in a sunny area with good air circulation. If available, select resistant varieties.
Avoid excess fertilizer. Use soaker hoses or drip irrigation. Raised beds or furrow planting also ensure proper soil drainage.
Timing of watering is important. Apply water to garden beds in the morning, between 2 and 10 a.m.
Gardeners are instructed to keep soil evenly moist, but what does that mean?
The "finger test" is a simple way to test soil moisture. If you stick your finger into the soil up to the second knuckle and the soil feels dry, then it is time to water. If the ground feels moist, then wait before irrigating.
Keeping the soil evenly moist is a good way to improve yields of garden crops, and will also reduce the spread of fungal disease.
I am looking for a climbing vine that can handle full sun. The plant would be in a large pot on my patio. I have tried morning glory and wisteria but have not had good luck. I would appreciate ideas.
Marilyn Larsen, Sacramento
According to UC Master Gardener Debbie Rogenmoser, a variety of vines can be grown in full sun such as Carolina jessamine (Gelsemium sempervirens), jasmine (Jasminum), potato vine (Solanum laxum) or violet trumpet vine (Clytostoma calystegioides), to name just a few.
To find information about these and other vine options, check the UC Davis Arboretum All Stars website (at http://arboretum.ucdavis.edu/arboretum_all_stars.aspx) or the Sunset Western Garden Book.
Don't forget to talk to your local nursery about options.
Keep in mind, all will have different watering, fertilizing and pruning needs.
There are a few things to keep in mind when growing plants in containers. First, be sure to choose a container with at least one drainage hole so that water will not drown the plant's roots. Do not use regular garden soil, as it is too dense for containers. Choose a good potting soil mix for your containers.
Plants in containers have to be watered more often than those growing in the ground. In hot or windy weather, they may need watering more than once a day. Test the planting mix with your finger; if the soil is dry beneath the surface, then water your plant. Water the entire soil surface until water begins to drain.
Plants in containers need regular feeding. A liquid fertilizer can be used or a controlled type of fertilizer can be mixed into the potting soil before planting. (Follow label instructions.)
Some vines may need support as you train them to grow upward. Consider adding wooden dowels or a small trellis to the container to help train your vine.
Questions are answered by master gardeners at the UC Cooperative Extension services in Sacramento and Placer counties.
Send questions to Garden Detective, P.O. Box 15779, Sacramento, CA 95852. Send email to firstname.lastname@example.org. Please put "Garden Detective" in the subject field and include your postal address.