April is still a great time to plant in San Diego gardens. You can now add subtropical plants like bougainvillea, gardenia and avocado. And keep weeding! Get those weeds out before they set seed. Feed almost everything in your yard.
Bulb Care
Many spring bulbs will have finished blooming this month. Some bulbs, like tulips and hyacinths require colder weather and, here, it’s easiest to treat them as annuals. You can just pull those out when they finish blooming. But for bulbs that are suited to our climate, like daffodils or bugle lily (Watsonia), you can cut off the flower stems, but don’t remove the leaves. As they die back, they feed the bulbs for next year’s growth and flowers.
You can help this process by giving your bulbs a light feeding. Only remove the leaves after they have turned yellow or brown. If you don’t want to see the dying leaves, try planting something in front of the bulbs or push the leaves down to hide them.
Take a look at my October 2020 post for suggestions from a local bulb grower and a list of bulbs that grow well in my yard.
Prepare your San Diego Garden Beds
If you’re planting this spring, prepare the area by adding organic matter to the soil first. Spread 2 to 3 inches of compost and incorporate that into the soil before you plant. You can also add a complete fertilizer if you’d like.
If you use manures, add them at least two weeks before planting and water well to remove salts from the surface of the soil. When using chemical fertilizers, put those on just before planting.
Control Ant Populations and Keep Ants off Trees
Start controlling ants now while their populations are low. Insecticide sprays are not effective because they only kill foraging ants. They also kill many other insects, and may contaminate surface waters which kills aquatic organisms. Insecticide use is one of the reasons insect populations are declining rapidly. Studies show that in the past 50 years, insect populations have plummeted by up to 75%.
Sticky barriers will help keep ants off trees and are safer for the environment. Wrap a band of heavy paper or duct tape around the tree’s trunk. Coat it with something sticky, like Tanglefoot. Make sure tree branches aren’t touching the ground or other objects that would allow ants to avoid your sticky trap.
To control ant populations in your San Diego garden, try insecticide baits placed near ant nests and trails. Use baits that are enclosed in bait stations, and those with less toxic bait like borate. You can purchase prepacked bait traps or make your own using borate and sugar. Bait traps have worked well at my house. We start putting them out in late winter and early spring to keep ants away from the house and protect plants.
Take a look at the University of California Pest Management Program for more details and other less toxic ways to keep ants out of your home and manage them in your garden.
San Diego Gardens Tips Source
A lot of information for San Diego Gardens comes from the Master Gardener Association of San Diego County. They are a great resource for all of your gardening needs including planting, pests, vegetables, and water use. They even have a free hotline where you can get your home gardening and pest control problems answered.