Tag Archives: crop rotation

Thinking like a plant

Books-Vegetable gardening in the Southeast-smallGarden Primer bookBarbara Damrosch states, early in her 633-page Garden Primer book, that “Good gardening is very simple, really.  You just have to learn to think like a plant.”

One of the challenges of learning to think like a plant is that not all plants think alike.

When you’re wondering how best to take care of a particular crop, the first question you’ll ask yourself might be “Where can I find good instructions?”  You might, for example, start by looking at the cultural notes in our catalog, or by looking in the “Edibles A to Z” section of Ira Wallace’s book Vegetable Gardening in the Southeast, or Barbara’s Garden Primer.

Another question to ask yourself is, “What do I know about the needs and habits of this plant’s relatives?”  Plants tend to be similar to their relatives in terms of the conditions they need for germination or fruit set, the relationships they form with soil microbes, the strategies they use to spread their seed, and many other factors.

For example, if you know that luffas are related to pumpkins and cucumbers, you can guess that growing luffas will be more similar to growing pumpkins or cucumbers than to growing tomatoes.

photos mid fall 2011 177 luffa stages
Left to right, the progression of luffas from flower bud to mature fruit: buds, flower, baby fruit with spent petals still attached, edible young fruits, intermediate-maturity fruits, and mature fruits for retting and use as sponges.

Luffas (also called loofahs), like most crops in the squash (cucurbit) family:

  • prefer dryer soil than most other plants, particularly while seeds are germinating
  • have delicate root systems, but can be transplanted with care
  • can sprawl or climb
  • use tendrils to cling to surrounding plants or structures
  • have flowers that are very attractive to bees
  • have separate male flowers and female flowers on androgynous plants
  • are easily killed by frost

If I was sending a soil test to a lab and wanted a recommendation on whether to amend the soil before planting luffas, I’d check the box of another crop in their family (assuming luffas aren’t on the list).  If I was worried that an insect might be attacking my luffa crop, I’d run through a mental list of the insects that I’ve known to attack other crops in its family. If I wanted to make a guess at which nutrients are abundant in luffas (when picked small for eating), I’d start by looking up which nutrients are abundant in other cucurbits that are also harvested before the seeds mature, like cucumbers or summer squash.  If I wanted to  harvest pure, market-worthy seeds from one variety of luffa, I’d plant it at least 1/2 mile from any other varieties of the same species of luffa, based on the similar isolation distances recommended for harvesting reliably pure seeds of other cucurbits.

However, any plant will have some significant differences from its relatives.  For example, most cucurbits set their seeds in a wet environment, but luffas set their seed in a dry environment.  Thus the techniques we use to clean luffa seeds are very different from those we use for most seeds in the cucurbit family.

It might be tempting to focus your gardening efforts on one family, grow lots of its members, and really learn how they think.  But diversity of plant families in your garden is one aspect of agrobiodiversity, and will help ensure that the bugs or diseases that like one of your crops won’t like too many of your crops.  It’s also important to rotate your crops, and like many farmers and gardeners, we organize our crop rotation according to plant family.

For an easy way to learn which plants are in which families, take a look at our illustrated list of the predominant plant families in American gardens.

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Sweet Potatoes, Potatoes, or Both? Decide for your garden.

ginseng sweet potato (slips for spring planting)dark red norland (seed potato)

Don’t be fooled: potatoes and sweet potatoes may share a name, but these two crops are grown very differently. We’ve broken down some of the differences to help you decide what to grow:

Plant Family: Genetically, potatoes and sweet potatoes have little in common. Potatoes hail from the Solanaceae family: their closest relatives are tomatoes, peppers, eggplants, and other nightshades. Sweet Potatoes are most closely related to morning glory: they are in the family Convolvulaceae.

Crop Rotation: Sweet potatoes should be easy to fit into a crop rotation, while potatoes may be quite difficult. Potatoes should be rotated by 3-4 years with nightshade crops, while sweet potatoes only need to be rotated with themselves.

Plant Starts: While potatoes may be grown from any sprouting spud, it is best to start from disease-free Seed Potatoes. Sweet potatoes may be started at home by sprouting your own slips (green shoots off the mother root to be separated and planted), or the slips may be purchased.

Timing: We ship seed potatoes from March through April, directly from our grower’s farm. Our Virginia-grown sweet potato slips begin shipping in May.

Planting: Potatoes don’t mature well in hot weather, so it is best to start an early spring crop (we start ours in March) and grow a fall-maturing crop for best quality roots for winter storage (we start a second crop in June). It can be difficult to find seed potatoes after April, so order seed potatoes in the spring and store them in the refrigerator until planting time. We plant our heat-loving sweet potato slips in June.

Yields: Yields vary, but high-yielding sweet potato plants often produce as much as 5-10 pounds per plant. Potatoes may yield 3-5 pounds per plant, but this will depend on hilling: the new potatoes are produced above the seed potato, so new soil needs to be piled over the plants throughout the growing season.

Storage: Both sweet potatoes and potatoes can be stored for months without refrigeration. Light-sensitive potatoes must be stored in a cool, dark place (preferably 40-45°F). Sweet potatoes can be stored at room temperature so long as they are kept in the dark (otherwise they will start sprouting at temperatures above 70°F or so).

Check out our full Sweet Potato Growing Guide and Potato Cultural Notes.