July, it is the time of the year when air conditioning is as important in the garden as it is in the home. You, as the temperature rises, can cool off with an electric fan, a cool drink or by hiding away in a cool spot. Your plants are not quite that lucky; yet certain gardening techniques can be employed to help your plants through the summer months.
The benefits of air conditioning in your garden will show up in the form of increased production, greater resistance to disease and pests and, in general, a more attractive vista. An improper over-heated environment during the warmer months often leads to wilt, dropping of buds and yellowing of foliage.
Aeration of the soil is concerned with its exposure to the air. If this is lacking then your plants very likely will suffer this summer. Believe it or not but there are millions of tiny spaces between the soil particles and this is where air resides. Soils that become water-logged force out this air, a condition that leads to souring of the soil. How to provide adequate aeration should be your first gardening consideration at this time.
In the first place you should start in with the right kind of soil. Light or sandy soils usually have the best aeration, heavy, adobe or clay ones the worst. That is due to the fact that in heavy soils the particles are packed very closely together, thus allowing little space for air. Adding humus to such soils will increase their friability and improve the drainage, at the same time aiding aeration.
In the outdoor garden regular cultivation also improves aeration. It should be carried on mainly after irrigations and only when the soil has dried out somewhat After wetting down the soil it often tends to bake especially after being exposed to the hot sun. If left alone this strata becomes quite hard and seals off the surface; then when water is applied again penetration becomes difficult and the moisture may wash away, rather than sink down to the root level.
Another way to keep your plants more comfortable this summer is to keep them from becoming too dense. Roses especially like lots of fresh air and plenty of circulation between individual plants. This can be provided, in the first place, by proper spacing at planting time and then by pruning the center of the plant when growth becomes too heavy. Ordinarily roses should be pruned to an outside bud but if the plants are in cramped quarters it may be necessary to prune to inside buds, thus preventing the canes from interfering with each other.
Trees can also be pruned out from time to time. This is a fairly common practice in windy areas as it allows the wind to pass through. Opening up the center of a tree reduces resistance, allowing the wind to pass through. This minimizes damage from winds.
Check out The Summer Pruning Guide by Gennaro Grass
Air conditioning is also concerned with proper humidity. Do not let your plants dry out during the summer months. House plants will react favorably to being syringed off from time to time. This cools them off, just like a shower bath. It also raises the humidity and keeps the breathing openings clear of dust or dirt. Outdoors the same technique may be followed. Plants such as fuchsias, which like a moist environment, will be greatly spruced up by a cold water shower once a week during the hot months.