As a kid, I’d always thought droughts happened evenly, but it turns out that water availability is highly variable; there are micro-climates of soil moisture the same way there are hot spots and frost pockets. As long as we’re having this danged drought anyway, I’ve begun really paying attention to both the hardy plants and the drought resistant garden spots. Here’s what I’m learning:
- Organic matter counts. You’d think the top of the hill would have the drought and the gully at the bottom would be flushed green, but it’s not so cut and dried. The steeper slopes, including the scoured gullies, have a harder time hanging on to the really good soil. Without enough organic matter in the top few feet, it’s like trying to fill a sponge with water while you squeeze it in your fist.
Idea: keep plugging away at this. Add organic matter to your soils every year. Feed the soils, and the soils will feed and water your plants.
- Afternoon shade counts. Even if the garden bed gets sun again in the evening, having that break in the afternoon keeps the plants from evapo-transpirating their water quite so fast. In this nutty heat, the plants with what should normally be a little too much shade are vastly happier than those with a smidge too much sun.
Idea: Over head trellises are great, but often permanent, and overhead shade cloth usually needs a trellis-ish framework to stay up. But what about dragging out the makeshift badminton net and hooking up shade cloth there?
- Mulch helps a lot. Heck, even having closely planted plots helps a lot. In both cases, the straw or the strawflower, the shade provided to the soil even at that low level really counts. Just like crab grass dies if your lawn is over 3 inches (7 cm) tall, a close packed garden loses much less water to soil evaporation.
Idea: mulch. Next year, if there’s a dry winter, plan a closely planted garden for the summer, but ASAP get out there and mulch your garden.
Note: Do not mulch up against the stems of the plants, especially those in the rhododendron family (Ericaceae). You want small mulches that will break down this winter into good soil and you do NOT want a mulch volcano around each tree. That’s a recipe for fungal infections.
- Perennials have a serious advantage. Not only are they generally larger and closer together, they’ve had time for some good organic matter to build up underneath them and time for some serious root growth. It’s not uncommon for Prairie grass roots to go down 6 to 18 feet, and marvels like the compass plant and the bush morning glory send roots 30 or more feet. There are trees in the oases of the Sahara that apparently send down their roots nearly 100 feet. That simply can’t be done if you’re an annual plant.
Idea: stay tuned for Edible Perennials Week, in which I extoll the virtues of Jerusalem artichokes, rhubarb, asparagus, and other perennial vegetables and fruits.
- Fields help. The gardens that are up against driveways, near the wall of the house (especially a brick house), or otherwise on the sunny side of something big and built are having to cope with the heat that reflects off those materials or that builds in those materials throughout the day and is then released all night. The gardens and farm fields further from brick and blacktop, meanwhile, are luxuriating in the cooling effect of not just their evaporative transpiration, but also that of all their neighbors. It’s nearly impossible for it to be 90 F inside a temperate forest, no matter how hot it is outside: too much tree sweat.
Idea: Consider having your midsummer veggies in beds further from the house next year. Also, what about hanging a white sheet between your house wall and the garden bed that is withering under the reflected blast oven?