Do your roses lack vigor? Your shrubs seem sparse? Your tomato plants puny? It may be that they’re hungry! Plants take nutrients from the soil and, over time, if the soil is not replenished, will exhaust the supply available. It’s just like if you or I were to keep taking food out of the refrigerator without ever putting more in. Eventually the shelves will be bare and we’ll be starving.
In nature, this is taken care of automatically. Walk through a forested area or a meadow and you’ll see that old growth (leaves, stems, flowers) is dropped to the ground, decays (with the help of insects and worms), and then becomes part of the soil again—resturning the nutrients that had been absorbed into the plant back to the soil. Our gardens are not natural environments. We tidy up spent flowers and last year’s dead growth (taking away our plants food source) and yet we want all of our plants, whether they be edible or ornamental, to perform at their peak all of the time.
To resolve this situation, we need to take an active role in replenishing the nutrients in our garden’s soil on an ongoing basis. Healthy, nutrient-rich soil is essential to having a fabulous garden. The health of your soil will go a long way towards dictating the health of your plants. There’s an old saying along the lines that you’re better to plant a $0.25 rose bush in a $5.00 hole than a $5.00 rose bush in a $0.25 soil–meaning you’ll get better results if you invest in great soil and put in an average plant than if you were to buy a superior plant and put it in lousy soil.
Creating great soil:
Adding organic matter (leaf compost, composted manure, worm castings, etc.) to your garden restores what your plants have “eaten up”. For ornamental gardens, a good practice in spring, once your plants have emerged but before they’re so big you can’t see the soil anymore, is to spread a decent layer of organic matter around all of your perennials, shrubs, and trees. Some is better than none, but you don’t want to bury your plants either—an inch or so is usually what I aim for.
To generate enough of my own compost to service my garden I would have to have several compost piles on the go. I don’t have the space for that, so I need to get my organic matter from elsewhere. Fortunately, the City of Toronto provides compost free to anyone who wants it–as long as you’re willing to go to the local waste transfer facility on Saturday morning, sit through a long line of other eager gardeners, and then shovel and haul it yourself. Other municipalities have similar programs, some of which require payment.
If I was a less frugal gardener I might consider ordering a cubic yard or two of compost from one of the local companies that will deliver it to your driveway in huge square sacks. If I had a smaller garden I might just buy bagged composted manure at my local big box store. On occassion, I have travelled a bit north of the city to buy shovel-your-own horse manure, which I then composted myself for a season before using. It was certainly great for my garden, but since I drive a hatchback, not a truck, it’s a bit of an awkward (and extremely fragrant) excursion.
In the fall I don’t get rid of the leaves that fall in my yard—I pile them on my garden! I’ve even been known to pick up my neighbours leaves (which they’ve nicely bagged and placed on the curb for me) and pour them on my garden beds. In the spring I pull off the ones that haven’t decomposed and put them in my compost pile. If you have a leaf shredder (or a metal garbage can, a string trimmer, and a pair of ear plugs) you can shred the leaves before pouring them on your garden—the pieces will be small enough that they’ll decompose right in the garden.
For my vegetable beds I clear out all the spent plants in fall. In the spring, part of my preparation for planting is to spread a significant amount of compost over the garden and then plant right in it.
The past couple years I’ve also been spreading a dusting of Spanish River Carbonatite over the vegetable beds—it’s an organic product, produced in Northern Ontario, that restores nutrients and minerals to the soil that are hard to come by with compost alone. The claim is that it increases the yield of your plants and also improves the Brix count (i.e. sugar content) and nutritional value of produce. I haven’t run a true test myself (I don’t have the patience to only treat half of my tomato plants with the product and then monitor them against untreated plants–I’m just not that systemic!) but from what I’ve read and heard from horticulturalsts who know a lot more about soil science than I do, I believe this product is worth using. It certainly hasn’t hurt my garden.
In order to perform up to our esthetic standards, some plants that are heavy feeders, like roses, need more than just a single topping up of organic matter. I sprinkle a half cup or so of magnesium sulphate (Epsom salts—the same kind you use in the bath to soak your garden-weary muscles) around all of my rose bushes in early spring. Good rosarians I know feed their roses with some sort of fertilizer (organic or synthetic) every two weeks from spring until the end of June. As I mentioned in this post, additional interventions may be required if your plants show signs of nutritional deficiency.
While all plants take nutrients out of the soil there are some plants that actually put nutrients back into the soil while they grow. Plants from the pea or legume family (aka Fabaceae) “fix” nitrogen in the soil, so if you grow them you not only get to eat peas, you’re also feeding whatever else you grow in that spot next.
Keep the refrigerator full:
So when plants that used to perform well in your garden start to dwindle off, think about your soil as a potential cause. Other things can cause less than vigorous growth and bloom (including pests, diseases, lack of pruning, and increased competition for sun and soil resources from maturing trees and shrubs), but if you haven’t been feeding your soil on a regular basis, there’s a good chance that hungry plants are the root of your problem. Don’t let the cupboards go bare–replenish your soil on a regular basis so that your plants will thrive.