If you haven't been on summer vacation yet, the following tips by Rhonda Ferree, Horticulture Educator with University of Illinois Extension, might be useful as you plan. Most gardens can withstand neglect for a long weekend, but extended vacations usually mean lots of lost work and harvest and can mean lots of catch-up jobs upon return.
Vacationing gardeners with lots of produce can have neighbors, friends or relatives harvest the crops. This can eliminate overripe fruits or over-extended plants, cutting down on potential insect and rotting problems. If you can't find someone to pick the produce for you, you might be better off removing the developing fruit. During the summer, with the exception of some squashes, few fruits and vegetables will go from bloom to ripe fruit within two weeks.
If the soil is dry, water before you leave. A good irrigation will last 10 to 13 days. Mulching also prevents water loss. Mulches should be used for weed control as well as for growth regulators. They tend to make gardening easier and more efficient. Water thoroughly before applying mulches. Apply mulches no more than 4 inches thick.
If you can afford it, consider a timer system, even with above-ground sprinklers or drip-irrigation hoses. Many home improvement stores have timers that can be programmed daily or weekly. Program timers to provide an inch of water or two hours of sprinkling at least once a week. If temperatures are forecasted to be in the 90s, program twice weekly for two hours each time. Don't forget deep watering of trees and shrubs if gone for an extended period.
Walk through the flower garden and deadhead all flowers thoroughly. Those with an extended bloom time will respond by producing more flower buds while you're gone. When you return, you should have some flowers waiting.
Plan to leave with a weed-free garden. Cultivate, hoe and mulch just before leaving. Spray pest-susceptible crops such as cabbage and eggplant with insecticide and disease-prone crops such as tomatoes, with a fungicide.
Watering containers and flower pots may be more difficult especially if weather is hot. Consider moving pots to an overhang, under some trees, or on the north side of the house. This should minimize water loss, though some will still occur. You might even set a water hose and timer to water the containers, baskets and pots while you are gone.
Mow the grass, but not shorter than normal which might stress it. If temperatures are hot, the grass will go into dormancy and won't need mowing. If weather is cool, you may have long grass when you return but at least your flower, vegetable and fruit plants won't be suffering.
You may come home to surplus produce, but advance planning for weed control, pest control and watering may keep the garden in production for the rest of the season.
Local Contact: Rhonda J. Ferree, Extension Educator, Horticulture, firstname.lastname@example.org