Saturday, December 11, 2010

What is an Heirloom Plant, Anyway?

Last year my sister risked extreme boredom by asking me a gardening question: is there a difference between heirloom and hybrid tomatoes? Well, here is my humble (yet extensive) opinion on the subject of heirloom plants.

Technically, the difference is in the breeding of the seed. Heirloom seed has been saved and passed down for many years. It is created by cross-pollinating two plants of the same strain, or by self-pollination, while hybrids are created by carefully cross-pollinating one strain with another. It is usually done to create a plant with optimal characteristics of both parents, for example to make a very productive tomato plant with resistance to a particular disease. Supposedly if you save seed from a hybrid crop and plant it the next year you never really know what you'll get - the babies may be a throwback to one of the parents or grandparents, which may not have been very good plants other than having one particularly desirable trait. Heirloom seeds, on the other hand, will stay true to their type unless they have been cross-pollinated in your garden.

Hybrid plants usually give better yields. They often produce earlier in the season. They sometimes are resistant to certain diseases, fungi, or pests. Heirloom plants, on the other hand, may be better adapted to a particular climate or soil, and are sometimes more resilient in the face of heat, drought, or poor drainage.

One of the most highly touted pros of heirloom produce is that it tastes better than produce from hybrids, and I have found this to be true - these plants did not stick around for decades and sometimes centuries for no reason.

Fans of heirlooms also sometimes claim they are more nutritious than produce from hybrids. I have never seen any evidence of this, so I just don't know if it's true or not. It's true that the plant often has access to more nutrients and more water per fruit, because it is producing fewer fruit. On the other hand, that doesn't necessarily mean it is using them. On a third hand, heirlooms also usually take longer to mature, giving the plant more time to transfer nutrients to the produce. Does the extra time help? IDK.

Another frequently cited benefit of heirloom seeds and produce is that buying them helps to support the hippies who are trying to preserve the biodiversity of our food supply. This is probably generally true, though heirlooms are probably popular enough now to attract mainstream producers.

I grew an heirloom sweet pepper plant a couple years ago. It grew to about 12 feet tall (it fell over and rambled about - it was more like a vine than any pepper plant I've ever seen) and produced only one fruit which never matured. I swore off heirlooms forever! Then the next year I accidentally planted an heirloom cherry tomato from some seed a friend gave me and loved that plant like a family member. Oh, so delicious and prolific (late in the season) and didn't slouch in the sun like my other tomatoes. So now I try to always plant a few heirlooms, and of course a few hybrid plants too.


  1. It seems like the take-away message is that neither the hybrid or heirloom label is a guarantee of quality (and it depends how you define quality anyway) so I guess this just means you try stuff out and see what happens. That seems to be what gardeners do anyway most of the time :)

  2. yes, and they share tips and produce with one another, so everyone doesn't have to try everything for themselves.