Intensive Cultivation Methods

It is spring and plants are growing fast, taking up more space every day. At this time of year I find myself scrabbling around to find room to move seedlings, wondering why I planted that thing there, and straining to find a place for the next crop. I never have enough garden to grow everything I want, particularly as I add about 10 new varieties each year.
How do you cram 60+ kinds of vegetables into beds that total just over 500 square feet? What should I do with all those flower seedlings and bedding plants? In essence, how do I get the most from every square inch of my outdoor and indoor gardens?

Fanatic growers have struggled with these questions and have come up with remarkable solutions. The methods of intensive cultivation are not for the casual gardener. You have to plan carefully, have a thorough knowledge of the growth cycle of each plant and be willing to experiment with unusual techniques.

The Gurus of this movement are Alan Chadwick and John Jeavons. Jeavons’ book, How to Grow More Vegetables than you ever though possible on less land than you can imagine, is a classic, packed with information but a bit overwhelming on first reading. A more accessible book, based on similar ideas is High-Yield Gardening by Hunt and Bortz. If you want to garden intensively, it pays to have the experts at your fingertips.

Intensive Soil Preparation
Intensive gardening (sometimes called French intensive or biointensive) rests solidly on exceptional soil management. When you ask your soil to produce twice the amount of vegetation as normal, you have to treat it impeccably (see previous soil articles).

Chadwick and Jeavons both suggest double digging and lots of compost to create topsoil that is as much as 24″ deep. A more ecological approach using minimal soil disturbance, adds compost tea, cover crops, mulching and organic nutrients to the mix. Match your cultivation method to your soil type (see soil articles) and aim for a deeply fertile soil tilth that is rich in life and minerals. If you allow fertility to sag, so will your harvest.

Raised Beds
Intensive cultivation uses raised beds (see raised bed article). This is necessary to gain space that would be lost to pathways and to maintain access to the closely planted beds. In my greenhouses, the plants are often so dense they threaten to take over the pathways; I have to resort to hacking off the overhanging leaves just to get in. With each year of cultivation, particularly if you treat with compost tea as I do, your beds will naturally get increasingly productive.

Plant Spacing
An unusual element of intensive gardening is the closeness of planting. Instead of rows, a particular crop (for example cutting salad) is often sown in a block. Seeds are scattered fairly thickly and the thinnings harvested as soon as edible. My beds are marked at 2′ intervals so I can plan each block of 8 square feet separately (2′ long by 4′ wide). This helps when I do intra-seasonal crop rotations (see below).

Seedlings are transplanted in staggered patterns rather than straight lines. The plants should be close enough that their mature leaves touch or even overlap slightly. This creates what is termed living mulch in which weeds are smothered and the soil protected from ultraviolet rays and drying out. In general, intensive spacing is about ¼ to 1/3 less than recommended on seed packets. One drawback: I sometimes forget how big my plants grow and find them squeezing out the ones next door. Intensive spacing is not the same as crowding!

Companion Planting
While single types of vegetable may be planted as a group, many different varieties do well together. Fast growing, shorter plants such as radish will grow happily next to slower, taller plants such as peas. Interplanting takes into consideration the characteristics of each vegetable — speed of growth, time to maturity, shape, and type of vegetable (root, fruit or leaf) — and matches it with suitable varieties to make best use of growing space over the whole season.

In February, I planted alternative rows of fava beans and spinach so that the spinach would get some protection from the heat. I tend to grow tall varieties of peas and runner beans to make use of as much vertical room as possible. The shade produced is great for salad greens and winter Brassicas. When in doubt, grow upwards to maximize all the space possible.

Some plants not only work well together physically but also have mutually beneficial effects. Sow certain varieties together and both will do a little better: radishes are good companions to both cucumbers and lettuce; onions and garlic help many plants repel insects; tomatoes and basil go well together, in the ground and on the table. Louise Riotte has a wealth of examples in her fascinating book, Carrots Love Tomatoes.

Succession Planting
I love my plants, so it is a little traumatic to wrench them up and toss them on the compost pile. This is just what I need to do if I really want to keep my garden productive. As soon as one crop begins to fade, it has to be ruthlessly removed to make room for a new one. When early season crops such as lettuce, spinach, pak choi, and peas are harvested, it is time to replant with beans, beets, and corn.

Every garden can have at least three seasons of plantings — cool weather plants in spring, hot weather plants in summer and cool weather plants again in the fall. With plant protection and greenhouse, the season can be extended until only January and February are a little short of fresh green vegetables. Even then, roots crops are still available.

If possible, only plant what you can realistically use or give away and keep putting in short rows of similar varieties every 2 – 3 weeks. This stops your family getting tired of too many greens and saves you from a glut of lettuce.

Crop Rotation
In all intensive gardening, particularly succession planting, crop rotation is absolutely central: never plant the same crop in the same place next time around. I always keep in mind the simple mantra: Give, Take, Rest. This translates loosely to planting legumes (peas and beans) first, heavy feeders such as tomatoes, brassicas, corn, etc. next, and finally the light feeders or root vegetables last. I think of the light feeders as giving the soil a rest from all that above ground activity. With reliable crop rotation, I almost totally avoid depletions and diseases.

When I first found How to Grow More Vegetables by John Jeavons, it was an eye-opener. Here was a way to make my small garden feed the whole family and more. With time and experience, I no longer slavishly follow his advice, yet I know these ideas and practices have become second nature. Apply only a few suggestions of intensive gardening and you too will have the satisfaction of getting the absolute most from your garden.

Marjorie Hunt and Brenda Bortz: High-Yield Gardening
John Jeavons: How to Grow More Vegetables
Louise Riotte: Carrots Love Tomatoes: Secrets of Companion Planting for Successful Gardening