IN THE GARDEN : Healthy Plants Depend on Well-Prepared Soil : Organic amendments, rough-textured soil give new growth best chance for success.
With the fall planting season in full swing, this is a good time to review how things should be planted--those tips and techniques that can ensure the success of any planting effort.
A good beginning requires a good soil, one that does not get too hard or too wet. Organic amendments are the best addition. By the sack or by the truck load, these planting mixes--not planter mixes or potting mixes--usually composed of specially treated sawdust or ground bark, fluff up a soil so more air and water can get into it and any excess can pass right on through. Bags are available at every nursery and there are instructions on the back.
This material must be thoroughly mixed with the existing soil but recent research has suggested that you can overdo it if you use power tillers to do the mixing.
Leave Some Chunks
You do not want to destroy the texture of the soil by beating it into the consistency of dry flour. There should be some small chunks of material left, so the soil has a slightly rough texture. This helps preserve beneficial soil organisms and keeps the soil from repacking too tightly. The surface should also be slightly rough when finished. That will help keep water from running off, and a crust will be less likely to form.
Mix the soil amendments and soil with a spading fork or spade, or even a small trowel-sized fork if you are doing a small area. If you use a power tiller, don’t linger too long in any one area or you will literally beat the soil to death.
Be sure to mix in some fertilizer along with the amendment, one that is high in potassium and phosphorous, with numbers such as 8-20-20 on the label. Amending a soil is hard work, but this is one reason the cooler weather of autumn is a favored time to plant.
Wet Area Ahead of Time
You should never work a dry soil (and never, never work in a wet soil), so be sure to thoroughly wet the area to be prepared several days in advance so it is just moist when you begin adding the amendments.
You should also never plant in a dry soil, so after preparing the soil, water it thoroughly once again and wait a few days before planting. While you wait, arrange the plants--still in their nursery container--or the bulbs, on top of the flower bed and use this interval to study your planting plan.
If you can’t plant until the following weekend, water once again midweek. It generally takes about three days for a just-watered soil to dry enough to be only “moist” and perfect for planting.
If you are planting trees or shrubs, you can prepare just the soil that comes out of the planting hole, adding amendments to the pile of dirt set off to one side. Some recent research here, however, suggests not adding amendments, but simply pulverizing the soil, perhaps by working it through a large piece of screening (with half-inch openings), so there are no clods. If this sounds too radical, try adding only a little amendment.
Don’t Dig Too Deep
Recent findings also suggest not digging holes too deep, at least in the very center. Trees and shrubs do not like to end up deeper in the soil than they were in the nursery container, so leaving an undisturbed pillar of soil directly beneath them helps ensure that they will not settle into the ground when freshly dug soil recompacts. Any excess soil should be formed into a little dike around the plant, what gardeners call a watering basin, to help funnel water to the root ball of the plant.
Try not to set plants too deep in the flower bed, either. The trick here is to dig a small hole and then press the soil back in around the plant, pushing some of the soil under the plant in the process, so the soil is somewhat recompacted. It’s very important to shove hard on the soil that goes back into any planting hole. If it is not recompacted, water will move through it so quickly that the root balls of plants will never get wet. Lean on it!
If you want to avoid weeds and keep rain or sprinklers from muddying your nice new soil, use more of the soil amendment as a mulch between new plants. Botanic gardens use wood chips as a mulch around everything, but finding a source for these is almost impossible, so other materials will have to do. Just make sure they are not so fine that they blow away during the next Santa Ana.
Water With a Wand
Watering with a wand--those long tubes that go on the end of the hose and have some kind of bubbler attachment at the end that diffuses the force of the water--also helps make sure each new plant is watered without muddying the entire area. Barely turn the water on and let it trickle around the base of each new plant. Watering only the new plants with a wand also helps prevent weeds from sprouting, at least until the first rain, but by then the plants will be bigger and more able to compete.
You can also use a sprinkler, but do not water with a spray attachment on the end of the hose, or worse yet, with your thumb clamped over the end. Watering from above like this will destroy the surface of the soil, causing it to cake, excluding air and water, which will just run off when you try to water next time.
Be sure to spread snail bait around new plantings the minute the last one is in the ground, if you want to find them there in the morning.
