Methods to ensure fruiting of Persimmon Bonsai

---

Princess Persimmon, Diospyros Rhombifolia, is one of the species I’ve grown fond of since coming to Kouka-en. It’s no surprise they are becoming more popular; the bright orange fruits bring some warmth to the cold, miserable winter months. Today’s post will help you identify the requirements of fruiting and problems you may encounter. I hope this information will help you enjoy your tree for years to come.

Maturity and Flower Identification

The first thing to consider is the age of your tree. Persimmon will not flower until maturing around 7-10 years depending on your climate zone. If you acquired yours as a seedling you’re gonna have to wait. I don’t recommend buying these as seedlings for bonsai since they are dioecious with rare instances of being self pollinating. You won’t know if you have a male or female until it’s too late, you’re old and angry at your tree for being a boy. Only females bear fruit.

If your tree is mature, flowers sprout from larger buds, the first node of new shoots with leaves extending there after. Identifying the sex of your tree can be pretty tricky if you’re unfamiliar. The difference from the outside is that the female flower has more of a round urn shape and the calyx (the green petals behind the flower) are larger as well, though there is variation among different cultivars.

Flowering and Pollination

There’s a lot of points to make here but I’ll try to keep it concise. You will need both a male and female to produce fruit. There is a 2-4 day window to pollinate once the flowers have formed but the sooner the better. During this time keep your bonsai sheltered if there will be heavy rain as flowers soften when wet or can be broken off. Some of the female flowers may become fertilized by insects if the male tree is near but it isn’t a guarantee. This can be problematic as unfertilized flowers will develop fruit through parthenocarpy but most, if not all, will drop shortly after to conserve resources. Last but not least, western varieties are incapable of pollinating eastern varieties and vice verse ie: D. Virginiana cannot pollinate D. Rhombifolia.

A simple method to pollinate is to take a fine, clean, paint brush, insert it into a male flower, stir gently, picking up pollen and transporting it into a female flower. Repeat for each flower. The pollen is quite fine and difficult to see but it will be on the brush. You won’t have to wait more than a week from this point to watch the fruits start forming.

Low phosphorus levels have been linked to fruits dropping in garden trees. A balanced fertilizer through the growing season is recommended.

This year I wired my shohin persimmon to better display the fruits in the future. I left the fruits on until this point to document them at the half way point after pollination. I have since removed the fruits and defoliated and pruned to better develop the branching as well.

Gibberellic Acid

Gibberellins are growth hormones which regulate developmental processes, stimulating cell division and elongation; in this case flower and fruit development. Synthesized gibberellic acid is is commonly used among citrus farms to improve overall yield quality and reduce defects. The important part here is that this can be used to get your tree to fruit without a male plant.

While blooming, the flowers can be sprayed with diluted gibberellic acid (concentrations may vary by producer) and the fruits will be stabilized. They will still develop seedless but will be carried to ripeness and hold through as long as pollinated fruits. A side effect is that without seeds, the fruits will be smaller which isn’t such an issue with shohin or mame trees. Pollinated flowers can also be sprayed as a redundancy without consequence.

Fruit selection

Keeping your trees in good health is a priority. Thusly, it is good to thin out any extra or unnecessary fruits while they are still green, leaving a few extra in case of dropping. Vigor can be balanced by leaving an even distribution of fruits among branches. Cutting to an odd number of fruits is common practice for display.

A note about Pruning and Defoliation

Flower buds can be identified during the dormant season as significantly larger than just leaf buds with a visible sheath. On the year you want to display, do not cut flower buds. If defoliating is done too late flower buds may not fully develop on new shoots before the end of the year. This can vary among climate zones but is typically done mid to late spring. If you are defoliating to increase ramification it is also best to remove any fruits you may have to maintain energy in the branches.

• Facebook
• Instagram