Improve your soil

By Dorothy Dobbie

What to do now for springtime planting depends on what and where the planting is taking place. Requirements for container planters versus veggie growers versus perennial gardeners can be quite different.

Container planters

Perennials planted in pots can find a home in the garden at this time when it is easier to see where the open spots are. If your perennial is in a liner pot, plant the liner pot with the perennial in it; then you can simply lift the whole thing in the spring and put it back in the decorative pot.

Annuals can be discarded on the compost pile or wherever. If there are garden beds, simply put healthy spent material on top of the gardens. The dead plant will break down over winter and add nutrition to the soil.

Clean the pots. Get rid of any residual fungal or other unwanted residue.

When was the last time the planting medium in pots was replaced? Chances are it has been two or three years or even more. Smaller blooms and more disease may also indicate that it is time for a change. This fall, empty all containers. Or, if they are very large, remove the top one-third of the material.

Don’t discard all that valuable soil. Spread it on the lawn or over the garden beds. The earth fauna will soon regenerate the spent material, adding microbial life and bringing up nutrients from far below the surface. Lusher lawns and better plant growth will result.

Either refill the containers now or wait till spring. Doing it now will allow the soil to settle over winter and leave plenty of potting room next season. Consider adding some natural garden soil to the pots, about 25 to 30 percent of the total. This will inoculate the material with life that will help plants grow next year. Adding compost to the mix will be even better.

Perennial gardens

The “perennial” discussion is whether to cut back plants in fall. To some degree, this will depend on the gardener’s sense of aesthetics and where they live. In Zone 3 gardens, the advice is to leave this chore till spring, but this advice is useful to more benign climates as well, unless you have had severe fungal or other disease this season. In that case, remove spent foliage and discard or burn. Do not compost.

Leaving the plants to fall on their own has several benefits. First, this provides an overwintering place for beneficial insects such as native ladybugs (the Asian kind look for warm places in and around the house). Secondly, the fallen foliage collects snow, protecting the root crown of the perennial from freeze and thaw damage. Thirdly, the spent foliage will return their nutrients to the soil to nourish a new season of growth.

Should you cultivate? Recent studies show that this is only useful if there has been an infestation of some unwanted creature that might have laid eggs in the vicinity. Other wise, leave the soil undisturbed.

Now is a good time to add a top dressing of compost, topsoil or the fallen leaves from your trees (mulch them with your lawn mower to help them decompose) and you can do this with the spent plants in place. They will break down over winter and do their part in making healthy soil for growing in next spring.

This is also a good time to divide perennials. The soil will still be warm enough to promote root growth before freeze-up so plants get a good start in spring. Fall dividing and planting shows where there is room to accommodate new plants.

Remember, this is general advice. There may be areas of your garden that might need special attention, and you should seek local advice on these issues.

Don’t just rake your leaves, mulch them and spread them over your garden.

Vegetable gardens

Because vegetable gardens are used intensively, they pose more of a problem in maintaining soil health. Firstly, most of the vegetables are foreign to the soil in which we grow them. We plant them in tidy rows to support our own needs, and to keep the resulting weed growth down, we till the soil.

There are both plusses and minuses to this. Tilled soil makes it easier for roots to establish, and neat rows makes it easier to harvest, and manage weeds and insects.

But each year the plant must establish a new eco system. Harmful nematodes and other foes have not yet located their presence. But as time goes on, things change and the crop that did so well in year one begins to fail. Gardeners deal with this by rotating their annual crops, moving them to different locations each year. Exceptions are the perennial crops such as asparagus and rhubarb or herbs such as mint and thyme.

Clean up old foliage which may contain disease and insect eggs. Dispose of it. Pull any emerging weeds. Till in areas where there were insect infestations.

Now is the time to add compost. If you don’t compost or you don’t have enough, purchase it at the local hardware or garden centre. You can dig it in; 2 to 3 inches in depth is a good rule of thumb. Anything deeper may not allow the cold to penetrate far enough to kill overwintering disease and pests. You can add more once the ground freezes.

The goal is to develop soft soil with good tilth. Tilth is the ability of the soil to hold air and moisture. Adding organics helps this as it encourages the activity of microbial life and in so doing releases the nutrition into the soil in a form that plant can use. If you squeeze a handful, it should hold its shape for a few minutes when you open your hand. q

Most kitchen and yard waste can composted into valuable mulch.