It is time for planting warm season vegetables. They require higher soil and air temperatures and are always planted after the last frost date. Here in Longmont that date is generally May 15. So, planting tomatoes, peppers, summer squashes, pumpkin, eggplant, cucumbers, melons, and beans should be safe. Once planted, many will grow and continue to produce until late summer or even early fall.
The cool season vegetables may need to be pulled now as the nights stay warmer.
- Yellowing and drying out leaves
- Greens tasting bitter and radishes being tough
- Greens bolting, i.e., producing flowers and seeds
When planting seeds or plant starts where cool season vegetables have been planted, refresh the soil with compost.
Now, when those pesky pests arrive (and they will), the university extension services recommend a program called Integrated Pest Management or IPM. It is a science-based approach that reduces the need for pesticides.
First, Cultural Control: Plant the right plants in the right place and plant varieties that are best for our region. Also, look for varieties that are disease and pest resistant. Encourage beneficial insects to be in the garden by inter-planting flowers such as marigolds, zinnias, cosmos, sunflowers, salvia, and yarrow. These will attract lady beetles (Lady bugs) Lace wings, parasitic wasps, and hover flies which will eat destructive bugs like aphids, thrips and spider mites that feed on your plants. Unfortunately, the pests usually appear first before the help arrives. So be somewhat patient. In addition, water appropriately and do not over fertilize.
Second, Mechanical Control: Physically remove pests by hand pulling or spraying water on aphids. Sometimes just removing the stem that has been infected is enough.
Third, Chemical Control: Pesticides should be used when other non-toxic control methods have been exhausted and once a pest problem has developed to a point where it is severe enough to require action. Consider using botanical pesticides and synthetic organic compounds such as oils, soaps, and detergents. And lastly, use the least toxic pesticide necessary for the project and follow label directions.
In July we will look at what vegetables that will take us through fall and general garden care.
Colorado State University is offering a free, online vegetable gardening course. If you are interested, the deadline for registering June 14. Click here to register.