As I stroll through Kamloops’ back lanes and community gardens, I am sometimes struck by the huge productivity of some gardens and also by the obvious unproductivity of others. Why are those gardens unproductive and how can we increase their productivity?
Unproductive vegetable garden soils usually lack organic matter. To increase productivity in new gardens, organic matter should be added once a year. In the Spring, peat moss, decomposed compost, and at least one-year-old manure will improve the performance of gardens. In the Autumn season, gardeners could include uncomposted materials such as fine bark mulch, sawdust (pine, spruce, fir – but not cedar) and dig in fresh (6 – 11 month old)manure. In all seasons, some form of nitrogen (the first of the three numbers on fertilizer bags) should be included. If you are digging in uncomposted organic matter, spread the organic matter evenly on your garden and turn the garden over with a shovel to allow for proper integration. To increase organic matter you can also grow, then dig in, “green manure” crops like fall rye, oats, peas, vetch, buckwheat.
Lack of Fertility
Unproductive vegetable gardens often lack fertility. If you grow organically, you can fertilize your garden with bagged or bulk animal manures, mushroom manure, compost, blood, bone meal, sea soil, alfalfa meal and a whole raft of other additives. It is very possible to feed a garden without spending a fortune. If you are not growing organically, you can use any number of granular fertilizers. Fertilizers which contain approximately the same amount of Nitrogen, Phosphate and Potash (the three numbers on the container) may be the best. So, something like 18-18-18 is great…and 13-16-10 is close enough. It is an excellent idea to get a quality soil test done every few years, for example, at MB Labs, in Sydney (mblabs.com) to establish your exact fertilizer needs. If you can’t test, consider sprinkling about 1.5 pounds of 18-18-18 (or 2 pounds of 13-16-10) per 100 square feet of garden. Dig the fertilizer in prior to planting.
Poor Soil Structure
Unproductive gardens often have poor soil “structure”. Soil with good structure forms into aggregates, little clumps made up of sand, silt, clay and organic matter. Think “snowflakes”. Soil structure can be improved by adding organic matter, avoiding rototilling, and not digging when soil is wet or super dry. I remember a co-worker once said “I water my whole [shrub] garden every two days, but I water my vegetable garden every day.” My co-worker’s implication was: “I really take good care of my vegetables” when in fact, my co-worker was watering way too often. While it is true that vegetable gardens love to get well watered, it is also true that vegetable roots really like to dry out regularly. Sandy soils lacking organic matter might need to get watered well every four days in midsummer Kamloops but sandy or silty soils containing lots of organic matter (there I go about organic matter again) will be quite happy receiving an inch and a half of water every six days. If you are over watering, always water in the morning to reduce the plant diseases on the leaves of crops like beans, tomatoes, melons, cucumbers, and squash.
Many gardeners allow weeds to overrun their veggie gardens. One way to control weeds is to mulch between veggie rows with materials like straw, chopped up leaves and grass clippings. Alternatively, heat loving crops enjoy growings being transplanted into a sheet of black plastic. If you don’t use mulches make sure to hoe, to a depth of about one centimeter, ideally with a stirrup hoe about every ten days. Have fun in the garden this year! And remember: if you want to make your veggie garden more productive: add organic matter, provide fertility, respect your soil structure, water thoroughly, infrequently and in the morning. And don’t let those weeds win. Grow early, grow late. For details related to the suggestions in this article, ask at your fine local garden centers.