Growing Tomatoes From Stem Tip Cuttings
So, you've picked your last tomato from your vines. They're starting to look sad, and you've realized that you should have planted some tomato seeds a while back to replace your plants.
Well, there's a quicker way to multiply the number of tomato plants you have, and yes, it involves cloning. More specifically, it involves taking stem tip cuttings from your existing tomatoes and planting them to grow into new vines.
Many people do not realize this, but tomatoes are among the easiest plants to successfully take cuttings from—almost easy as pelargonium geraniums. You don't even require any special rooting hormones to successfully grow tomatoes from cuttings.
The Benefits of Taking Tomato Cuttings
You have a clone of the plant you took a cutting from. If it was a particularly good producer or had particularly tasty fruit, the vine grown from the cutting should have the same characteristics.
Often tomato seeds from shop-purchased tomatoes will come up in the compost. Some of these won't be good, but others can turn out to produce really tasty fruit.
It is interesting in itself to see the variety of tomato types that come up from generic, hybrid shop brought tomato seed. I ate my first of a delicious beefsteak-like tomato for lunch the other day that grew from seed from a hybrid, shop tomato. This particular tomato plant would be a good candidate to take cuttings from, so I can still enjoy it long after the original plant has died.
You can slash about four weeks off the time until fruiting when compared to the time taken to grow tomatoes from seed. If you have a short growing season and harsh winter, you will have to keep your tomato variety growing indoors or in a hothouse to take full advantage of the next growing season.
I live in the subtropics where tomatoes will grow happily all year round, though fruit flies can be a pest during summer.
The Risks of Taking Tomato Cuttings
If you were to plant hundreds of heirloom tomato seeds, in most cases there would be a fair amount of genetic diversity within your population of tomatoes.
This means that if a disease comes and wipes out 99% of your tomatoes, you still get to keep the 1% that had a gene that allowed it to cope better against that particular disease outbreak.
If you had hundreds of plants grown from tomato cuttings that were all taken from an original plant that didn't have any resistance, however, you'd likely lose the lot.
If you take cuttings from a diseased plant, these cuttings will carry with them the disease. It will quickly spread to any new growth, decreasing the overall vigor of the plant.
It is advisable to only take cuttings from plants that are disease free.
What You'll Need
You'll need a good, sharp pair of secateurs to get the best results and not mash up the stem. Handle the cutting with care, as any damage may encourage rot. You can sterilise your secateurs under boiling water, bleach, or hydrogen peroxide if you want to really act like a pro. Though most of the time this shouldn't be necessary, as long as you have fairly clean secateurs to begin with.
You'll also need some pots and a reasonable seed raising mix to plant into, unless you are getting the cuttings to root straight in a jar of water.
So now, getting down to the nitty-gritty of taking tomato cuttings, I'll explain the steps:
- Select a thick lateral branch arising from the base of one of the lower leaves. Be careful when choosing, as tomatoes have compound leaves (a big, single leaf made up of many smaller, divided sections). This means that some of the larger leaves will look like branches in their own right but are not and taking a cutting of these and planting it will only result in disappointment.
- Measure about 6 inches back from the tip of the lateral branch, and then find where the next node (where the leaves join the stem) down is. Cut the stem straight across about half a centimeter under this node.
- On your cutting, remove the lowest two leaves and any additional really large leaves, as they may cause more water to be lost than the cut section of the stem can uptake, drying out the cutting.
- Cut off any flower stalks or green fruits right back to the stem, taking care not to damage the growing tip. This is so the plant does not spend energy trying to form fruit when it should be concentrating on establishing a healthy root system. Ideally, take the cuttings before the lateral branches start to flower or fruit.
- Plant the cuttings in pots two nodes deep, so that the mix is just above the second node from the bottom. Tomatoes are really easy, as they can form roots all the way along the underground section of stem.
- Water well and regularly. If you suffer a climate that will dry your mix out before you get a chance to water it again, you can place the whole set-up in a plastic bag and tie a knot at the top so that the humidity is retained. It is a good idea to keep your new plants out of direct sunlight, as this can cause the cuttings to wilt. Alternatively, you can place the cuttings into a jar of water as shown above until they form roots and then plant them out. I prefer to plant them into mix, however, and then transplant them to the vegetable patch.
- Wait for roots to form. It may take a couple of weeks, but you should soon see a burst of growth from your cutting and perhaps even roots coming out of the bottom of the pot.
You can now plant them out and they should take off, as long as you look after them that is.