Lynda Ellis, UM Extension Master Gardener in Anoka County, May 10, 2015
Do you grow, or plan to grow, vegetables? Let’s get them off to a good start, and manage disease throughout the season.
First, if you start seeds, purchase disease-free seeds from a reputable source. Look for disease-resistant or tolerant varieties for disease problems you have seen in the past. If saving your own seed, collect seeds only from healthy plants. Seeds can be started outdoors using winter sowing. If starting seeds indoors, use new potting mix with new pots or pots cleaned with 10% bleach. Keep seedlings moist but not soggy. Provide good air movement around plants. If starting seeds in the garden, wait until the soil is warm to plant. If using transplants, purchase them from a local reputable grower. Reject any transplant with dark, discolored or soft shrunken spots on leaves, stems or roots.
Before planting, clean all dirt and debris from tools, trellises, cages, etc. Sterilize tools with 10% bleach (mix 1 part bleach to 10 parts water) before using them in the garden. If possible, rotate your crops, planting them in a location where no member of the same plant family has grown for 2-4 years.
To manage plant disease, an ounce of prevention is worth a pound of cure. Examine plants weekly throughout the gardening season. Examine lower and inner leaves, as fungal and bacterial leaf spot diseases often appear here first. Examine upper and lower surfaces of leaves, fruit and stems. Identify the source of the problem before taking action. Use the online diagnostic tool “What’s Wrong with My Plant?” at http://www.extension.umn.edu/diagnose/plant/
Manage moisture. Use drip irrigation or water early in the day so that the sun dries the leaves and fruit quickly. Give plants enough space so they dry quickly after a rain. Stake tomato plants to keep them off the ground. Vining plants like cucumber and squash like to have something to climb on. Cover exposed soil with mulch, such as wood chips or straw. Do not work in the plants when they are wet. Fungi and bacteria spread under these and other humid conditions.
Remove weeds and diseased plant materials. Never remove more than 1/3 of a plant’s leaves. Remove rotten fruit, but do not mix it with the good; use two buckets. Diseased plant material can be put in the compost pile only if it gets hot. If not, put it out with yard waste or bury it in a non-garden part of the yard.
With a little care and monitoring, your vegetable garden will be better than ever. Remember, the goal of a vegetable garden is to have tasty vegetables. It is not important for the leaves to look pretty. For more information see: http://www.extension.umn.edu/garden/yard-garden/vegetables/ .