Cloning pumpkins!? Rest assured, there is no strange or evil scientific or genetic experimenting going on here. What is really being described is a form of plant propagation. It is similar to how strawberries, spider plants, and hundreds of other plants propagate themselves. What is different, unique and highly valuable, is that this technique has not been developed and used on Cucurbita before. It is the result of careful research, years of patient study and experimentation, and the help of several friends, Cloning has many benefits as you will see in the article
This article was written by Marc Sawtelle of Colorado Springs, Colorado.
My theory is simple…
1. Cloning can help produce superior genetic pumpkins quicker than using the cross breeding methods we all use now.
2. Cloning could save a great strain of ANY pumpkin which grew a record fruit, and enable someone to try all kinds of cross breeding combinations with that plant.
3. Cloning original plants can save a strain that might have just had a bad growing season. I know there had to be a few growers saying ” I think I really had a great plant going…but I’ll never know what it would have done since we had such poor growing conditions!”
Cloning is nothing new to the horticulture world. It is simply a plant propagation technique, and an open mind to try them on a plant which requires a lot of care in between the growing seasons. I experimented trying various cloning methods and techniques, and have seen other growers raise them without any different results than if it was a seed started plant.
One of the best advantages I noticed over a seed started plant, is once it gets rooted outside and gets some larger “outdoor” leafs, a clone has plenty of male flowers, and even some females to “practice” or “experiment” on as early as the first week in June. By the time the golden zone to pollinate rolls around, there are plenty of females and males to pollinate! No need to put all your hopes on just a couple of fruits, not when there may be 10-15 getting ready to bloom on a plant which can have many “main stems” if the grower so desires.
Successful cloning off the main vines is as simple as burying the vine in some soil, then waiting 7-10 days to cut the new plant from the main plant. Many growers bury vines during the season to give their plant an added root system which anchors and feeds the main plant. To make pumpkin clones indoors {or out}, the same basic principal is applied. Once the original pumpkin begins growing over the container and has a vine long enough which can be placed in another pot, all the grower must do is provide that vine a rooting medium for the plant to do what is natural for it; sprout roots.
Bury the entire vine 1/2 inch below the soils surface in the new pot. This is soon to be a new plant, of the same origin as the original plant. Place a heating pad below the pot the clone is in, and keep head on low or medium. The clone pot should be well watered, but not overly saturated. It is helpful to use vitamin B-1, Superthrive plant hormones, and Shultz 2-7-7{with micronutrients} Cactus Plus. Using similar fertilizers will work as well. Both the host pot and clone pot should then be put underneath a shop light which is kept on 24 hours a day. Check the clone plant after a couple days, and keep the soil moist in that pot. The host pot needs little to no water during this period. By stressing the host plant this way, the clone becomes less dependent on the roots at the base of the host plant, and is encouraged to sprout it’s own roots. After 7-10 days if you have given the new vine what it need to grow, the host plant can be cut away. Cut the old vine away from the clone as close to the soil as possible. Larger leaves which were buried earlier should be cut at this time. This will allow the new plant to not have to care for so many leaves initially, and allow the plant to root without stressing. You now have a cloned pumpkin plant which has the same genetic makeup as the host plant it was cut from! This process can be done again and again and again.
The uses of pumpkin cloning are simple. One can keep a good genetic plant alive for a new season and not worry about seeds. Also, if the grower has a short growing season, cloning can help get a jump on the season by allowing flowers to develop earlier than normal. This is because a newly spouted seed takes time to start flowering, and a clone is already producing them at the base of the plant.
Imagine if the 1999 World record Checkon plant was cloned! Since the plant produced only 34 seeds, having a clone off of that pumpkin plant would have allowed them to cross it this season and have more seeds from this wonder! Growers also may wish to keep a clone through the winter which they liked as a possible pollinator for the next season. Cloning just may be the next way to reach a 2,000 pound pumpkin.
The “how to” part is easy. The hard part is keeping up with them all winter. There are two ways to clone. The first is Tip cuttings, which I only have had an average of a 30 percent success ratio. The second, is the “pot to pot” method, which is the easiest. Both of these techniques are basic horticulture plant propagation methods used for house plants to get more plants from an original plant. Nobody I have known had ever considered using these methods on pumpkins. Since the DNA does not get altered from propagating a host plant, and all the original genetic makeup of the plant are the same, it would seem that cloning a great genetic pumpkin only would be as logical as breeding a great strain with another superior strain.
To do the pot to pot method, all that is needed is a couple shop lights, good high grade soil, a plant starter solution, and rootone. (optional, I do not need to use it anymore). Example: An outdoor late season side vine long enough to put a 5 gallon pot under is a good candidate.
Dig the ground out to be able to slide the pot underneath the vine, and cut a small notch out of the side of the pot which is large enough to allow the vine to rest on the soil in the pot, without having to bend too sharply on the side of the pot. The vine should be long enough to lay over almost all of the pot, and have two, preferably, three leaves to be able to bury one inch deep.
Once the vine is buried, make certain the top of the soil in the pot is fairly moist, but not too wet, and if possible, keep the original vine dry near the pot. After about a week later, roots should be growing on the plant in the pot, and the new plant should be growing a few inches over the pot.
To speed things up and keep the clone from stressing too much once cut off of the main plant, I make a small 45 degree notch in the vine going into the pot as close as I can to the surface of the soil in the pot. I cut the 45 degree notch out of 1/3 of the vine, which allows the new plant to still get nutrients and water, but forces the clone to start speeding up its root growth in the pot to compensate for its lost energy.
I wait about a week after this, and then I simply just cut the plant away where the notch was made, and remove the cutting from the original plant. A new pumpkin plant is then ready and alive to grow on it’s own.
To keep the plants alive all winter, simply bring in the new plant, put it under one or two shop lights, about 3 to 5 inches below the light bulbs, and then repeat the method over and over as needed. I supply a small breeze with a small fan set on low and aimed to blow only a slight amount of air around the plant to allow it to keep its stem strong.
I also keep the lights on either 18 or 20 hours on a timer. I have yet to see any difference in keeping the light on constantly, or for 18 hours. Less than 18 hours makes the plant get lighter leaves and a long, thin stem, and in general, a sick looking and unhealthy plant. Temperatures are kept around 70 degrees…an average house temperature.
Once spring allows planting outside, just harden off the plant as you would with a new seedling. If you desire earlier male and females, I have found the cloning method to help start a month or two earlier than the normal seed starting date. If you plan to do this though, the seed needs to grow for about 3 or 4 weeks, so it is long enough and has enough leaves to begin the pot to pot method.
I have managed to “fine tune” a few potting methods. I really am beginning to notice some small things pumpkins do that have never occurred to me when they are growing outside. I thought I should remove the new male flowers as they shoot out, as I thought it might help transfer the energy to help out with root development. Cutting them off seems to only DISCOURAGE side vines and new growth on the main vine, and no extreme or noticeably different roots are produced when culling the male flowers.
Also, if the soil is not “just right” when rooting is desired, they will not shoot out at the base of any leaves! What happens is they rely on the existing root system in the other pot to supply the needs of the new growth, until the soil moisture content and oxygen levels reach acceptable levels. A major sign is small leaves at the tip of the main vine and no side shoots from each leaf. Leaves also go from large to small, and sometimes yellow, as if a nitrogen or iron deficiency is occurring. Tips often die before the problem is even noticed or diagnosed in time, thus killing the entire clone.
Pests will also develop and thrive in excessive wet environments. Soil may be bone dry on the top 2 or 3 inches of the pot, perfect all the way to near the bottom, and soaked the last 2 or three inches of the pot. Too loose a soil is bad, as well as not loose enough. I will be experimenting for a while, I can predict, to get a perfect soil mix formula. Lets just say there are no soil mixes especially formulated for pumpkins on the market which could be purchased. One must mix several combinations together to create soil pumpkins can thrive in, rather than just barely exist.
