A rootstock is the root system of a common or hardy plant that will accept a graft of a less resilient variety. By grafting the stronger root a more fragile plant will gain strength. Often used on roses (particularly standard forms) and fruit trees, grafting with rootstocks allows us to grow a wider range of desirable plants. Sometimes when a grafted plant dies, it will sprout anew from the stronger root, but don’t be surprised when the resulting plant is nothing like what you expect. The new growth is only that of the original, less desirable variety of the rootstock.

Currently these roots are being used to grow bigger and more disease resistant edible plants. Tomato plants are the first to come on the market and, although they are more expensive to buy due to the facts that two plants must be grown together into one and there is an added human labor cost, the increased plant survival rate and prolific production is making them cost efficient. Grafted fruits and vegetables offer a safe alternative to genetic engineering.

Sometimes you can find plants for sale — particularly fruit trees — that give you a choice of rootstock. In this case you will be as interested in which will do best in your soil conditions as you are in choosing the variety of the grafted upper part. Some combinations will do better depending on what your garden has to offer.