May in the Garden
Weed, weed, weed. It’s important to catch the weeds while they are still small because they will compete with your other plants for nutrients, water, and light. Weeding is my biggest job in the garden right now, and I’m doing a pretty good job of staying on top of it – so far!
A repeat from last month: Mulch a two-inch layer of organic matter around your annuals, perennials, trees and shrubs to suppress weeds, and hold in moisture and keep the roots cool. Mulching around roses is a great way to keep them evenly moist and help prevent fungus growth by reducing water splashing and spreading spores.
NOTE: Don’t mulch around warm season vegetables right now because they really need the heat around their roots.
ROSES: Canned roses are good pickings right now at area nurseries.
Annuals To Plant: Ageratum, Amaranthus, Aster, Bedding Begonia, Bedding Dahlia, Candytuft, Celosia, Coleus, Coreopsis, Cosmos, Gloriosa Daisy, Impatiens, Lisianthus, Lobelia, Marigold, Nasturtium, Petunia, Phlox, Portulaca, Sunflowers, Sweet Alyssum, Verbena, Vinca Roses, Zinnias.
Perennials: Most perennial plants may be planted this month with good success.
Vegetables: Beans, Beets, Carrots, Cantaloupes, Corn, Cucumbers, Eggplant, Kohlrabi, Leaf lettuce, Lima beans, Okra, Parsley, Peppers, Pumpkins, Radishes, Summer, Tomatoes, and Watermelons
We are probably at the end of any significant rain in the coming months. Make sure your irrigation is turned on, and make any repairs if you haven’t already. I’m seeing a lot of geysers around town! Now I need to pay more attention to areas that aren’t being serviced well by my irrigation, so some regularly scheduled hand watering is in my future for awhile!
ROSES need about 1½ inches of water twice a week this month. The blooms have been spectacular this year so whatever weather and rain conditions predicated that, thank you Mother Nature!!!
EPIPHYLLUMS are still blooming so continue to cut off faded blossoms and mist frequently in hot weather but don’t over water. A good rule of thumb is to water when the soil is dry down to 1-1/2 inches.
Plants are continuing into a big growth period so continue fertilizing. Remember not to overdo the feeding, otherwise your plants will grow too aggressively, resulting in softer growth and a thirstier plant during the summer months.
Keep an eye open for iron deficiency to show up in plants. After our rainy season, such that it was, the soil has been flushed, which is a good thing, but minerals will be lacking so we need to amend appropriately. Watch for yellowing leaves with green veins. Feed plants with a fertilizer that contains chelated iron combined with zinc.
CYMBIDIUMS: May begins the main growing season. Good summer care is important Keep the plants in semi-shade. Cut off bloom spikes and fertilize with your favorite orchid fertilizer. If you want to go a very easy route, fertilize with 2 or 3 Tablespoons of Osmocote about once a month. Fertilizer will be released each time you water. Have your cymbidiums outgrown their containers? Transplant no later than the end of June. If you wait, you may not get blooms next year.
CAMELLIAS, AZALEAS and RHODODENDRONS: Start feeding with an acid fertilizer when they stop blooming. Use at half-strength so you can feed again two or three more times. Fertilize at 6-8 week intervals, finishing up at the end of September.
DAHLIAS: Give your dahlias a low nitrogen fertilizer. The goal is not such vigorous green growth, but those beautiful flowers.
Pest & Disease Control:
Warmer weather means that garden pests are waking up, stretching and getting ready to feast on all the new, fresh growth in your garden. Aphids are starting to appear in my yard so I’m blasting with water first, but if I see the problem getting out of hand, I will be a bit more aggressive with an insecticidal soap. I invested in a bunch of ladybugs which have done a good job so far, but I also keep a bottle of SAFER soap handy so I can spot-treat when needed.
Head out to the garden in the early morning or evening to find snails and slugs. They are out in force and can do lots of damage in a short period of time. This time of year I typically find giants in my garden, so I’m moving things around to expose them and open up the hiding spots. They’ve done damage to my cabbage leaves, and a lot of my succulents have taken heavies from snails feasting away on their soft leaves. If we have damp nights, hunting is usually very fruitful, so get out there with a flashlight and find those little devils!
If you have planted your veggie garden already, chances are you will be battling leaf mold on your squashes. Typically the cause is overwatering, but on the coast the cool, damp weather plays a heavy role. There are a few theories about how to deal with this problem organically. One theory says to dilute skim milk 50% with water and spray on leaves. (Only use skim because the fat in milk will get stinky out in your garden!) Another theory is using apple cider vinegar or baking soda diluted down with water. Sorry, don’t have a ratio for that but I’m going to try 1:4, water being the 4.
Watch for caterpillars and stay ahead of an infestation. Some caterpillars will turn into beautiful butterflies, so don’t over react when you see your first one or two. Just pay attention to those plants that tend to get infested. In my garden, that would be my Cecile Brunner roses, tomatoes and geraniums. My first line of defense are my birdfeeders. My theory is that if I attract birds to the garden and let the feeders empty out every couple of days, the birds will look for other food, i.e. caterpillars and aphids, on the plants in my garden. If that fails, I’ll spray with BT – Bacillus thuringensis. These will kill caterpillars only, leaving beneficial bugs alone.
On your roses, watch for rose slugs aka saw flies. Pay attention to the undersides of the leaves, looking for pale-green, caterpillar-looking slugs. They will strip a plant bare if you don’t pay attention. Spray your plants to wash these pest off, but if it begins to get out of hand, thoroughly spray with BT, including the undersides of the plants.
Aphids are beginning to appear on my brassicas and citrus trees. I’m spraying with the hose regularly, but if I can’t get it under control I’ll start spraying soapy water or use Safer insecticidal soap.
If you haven’t done so already, it’s time to prune back frost damage on your plants.
Don’t forget: Prune spring flowering shrubs such as azaleas and camellias when they finish blooming because they bloom on year-old growth.
It’s time to prune your hibiscus, lantana and other sub-tropicals. These plants need shaping and can be cut back by as much as half, allowing you to shape them and clean out for a healthier plant. Think whitefly on your hibiscus!
Pinch back your fuchsias, salvia and chrysanthemums to prevent legginess and promote fuller plant growth.
Thin out the new fruit on your deciduous fruit trees to about one fruit about every six inches. This is easier said than done, because I shudder to pull little apples off my trees, but I’ll get a better harvest for it and the tree won’t get so stressed.
LADYBUGS: Who doesn’t need more ladybugs in their garden?! I know they are a bit pricey, but buy a little bucket of these beauties and invite your neighborhood kids over for the release. Priceless…..
Don’t forget……..SUNSCREEN! HATS! GLOVES!
Credit where credit is due: This monthly garden chores compilation comes from a lot of resources, past and present, including: Sunset Magazine, Union-Tribune, San Diego Floral Association, San Diego Horticulture Society, San Diego Home & Garden, Anderson’s La Costa Nursery, miscellaneous tidbits found on the web, in the library, from fellow gardeners, and personal experience in the garden.