Cloned seedling off a 0.5 X 6.0 cm root cutting.
Paulownia root cuttings are my favorite method in establishing a paulownia plantation! Read on to find out why.
Starting paulownia by seed is not the only method of reproduction for the tree. If knowledgeable in the techniques, paulownia can be reproduced by vegetative methods. Almost any part of the tree can be used; root, stem, buds, or leaves.
Vegetative reproduction, asexual reproduction, miro-propagation, and cuttings are all techniques which produce clones. Clones are genetically identical to parent material single parent, the cutting.
If you have a particular tree you like and want another exactly like it, some form of asexual reproduction is best. Like the Chinese, we believe root cuttings are the practical choice over other techniques.
About Our Clones
- All our clones are dormant root cuttings.
- Dormant paulownia stock sprouting will be 70% or better. Direction must be followed.
- You need to cut roots to desired length. The reason I do not cut to length is because long term storage is much better.
- Number of cuttings per pound depends upon the length of cut and caliper of root.
- Average number per pound varies between 12 to15 cuttings.
- Allow 3 to 8 weeks for cuttings to sprout. Sprouting is dependent on the soil's temperature and moisture content.
Advantages of Root Cuttings
- You can clone your favorite tree with no special equipment or hormones.
- Since they are dormant, purchased cuttings ship easily with little damage.
- Also, dormant material can be held easier by cold storage until your planting schedule allows.
- There is no harding off/toughening up required as with green house seedlings. The cuttings are dormant, so they can take a lot of abuse and still come on strong! Cuttings the size of your index finger (or larger) do best in the field, for they have ample stored energy to get them started.
- There is no need to water when first planted. Personally, I can plant earlier in the spring about 4 to 6 weeks earlier than greenhouse grown seedlings. Frost is not a problem and the weather is cooler with more spring rains. When the hot weather does arrive, the cuttings have had the necessary time to establish themselves. They may still need watering during the season. However, the watering is more for growth, rather then trying to establish.
Care Before Planting
•For field planting, wait until the soil warms up. If planted too early, the wet cold soils will cause the cuttings to rot before they have a chance to sprout. In other words, it is a race between sprouting and rotting. Put the odds in favor of sprouting by waiting until the soils stay warm! In East Tennessee, that would be the last week in April or the first week in May, or when the ground temperature stays above 55ºF.
•Upon receipt, refrigerate until you are ready to field plant. They are packaged so that they can be stored for about 6 weeks in refrigeration. You need to check weekly for condensation on the plastic bags. If it develops, simply remove the roots from the bag, let them dry out for a day, and replace into a new plastic bag, wrap in a dry paper towel. The paper towel should wick any surface moisture off the root cuttings.
•Another method is to place into a soil-less potting medium such as sand/vermiculite mixture and simply leave outside in the weather unlit you are ready to field plant. You can wait till you see the first signs of sprouting as indication for planting.
•If the root cuttings are small, it might be best to pot the cutting into ½ to 1 gallon containers and let them grow in these pots for the first few months. You can expect a higher mortality (up to 75%) on cuttings less then .25" in caliper.
• Not necessary, but a good measure to soak the root cuttings in a fungicide for at least an hour before field planting. My current choice is Infuse made by Bonide purchased at my local farm co-op. It is broad spectrum, systemic, and can last up to 4 weeks. It is good insurance to help prevent field rot.
• Loosen the soil before planting by digging a hole, then refilling the hole with the loose soil dug. I prefer using a tractor with a chisel plow to break and loosen the soil. Weeds must be kept under control the first year, so I use a pre-emergent product call Princep 4L mix with Roundup, after tilling the soil. It works for about 6 weeks. After that I hole/mow.
• Planting orientation is also important. The cuttings need to have the same vertical orientation to the ground surface as when dug. The cutting will always sprout on the end which was originally closest to the ground surface. If planted upside down, it will sprout toward the center of the earth! I prefer to simply place the root horizontal and let it chose the sprouting end.
• Planting depth is also important. Place the sprouting end of the root cutting just below the ground surface to no more than 1/2 of an inch deep.
• Mark your planting with a survey flag to add in weed control and watering, which is very important throughout the summer months.
After Care Planting
• Do not water your root cuttings for the first few weeks! There should be enough moisture in the spring soil to keep the cuttings healthy. Too much water promotes rot. You can water once the sprout has emerge and the weather turns dry.
• Keep the weeds under control the entire summer. Use whatever means it takes. Paulownia is very intolerant to any type of shading or competition.
• Allow the cutting to grow naturally. What you need to do during the first year is just let the root system develop. Plan on pruning the trees the beginning of the second year to develop the first log of your future paulownia lumber.
In China, root cuttings are the method of choice for paulownia propagation. It is their method of choice for cloning. It is a low tech, highly successful technique that has been proven to work well for centuries. In short, if you have not every used root cuttings, you might give them a try.