JULY
2010

 

 

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

 

 

 

 

07-01-10

Question and Answer


Q. I have recently indentified a male persimmon tree on my property. I was wondering if a female could grow from the same root system, or does it need to be planted on its own. And if this is the case, do you know where I could purchase one?

Also, I have another tree that I thought was a plum tree; it bloomed before all the others, and it does in fact have purple fruit but does not get very big. Is it a plum and just ornamental or are the fruits edible? It has all the identifications of a plum tree.

A. American persimmon trees primarily have separate male and female trees, but occasionally a particular tree may develop a few flowers of the other sex. Male trees are more likely to produce a few female flowers than vice versa. Generally, to have reliable fruit production, it is best to have at least one tree of each sex. Purdue has an article illustrating the difference between male and female persimmon flowers at http://www.ppdl.purdue.edu/ppdl/weeklypics/6-14-10.html. North American Fruit Explorers have a helpful list of nurseries for many species of fruit http://www.nafex.org/supply_source.htm.

Of course it is difficult to identify whether your other tree is a plum without seeing it. There are a few species of Prunus that would have small purple fruit, but I cannot address its edibility without a correct identification. The Purdue Extension office in your county can assist you in getting the plant identified. You'll find the contact information for your county at http://www.ag.purdue.edu/extension/Pages/Counties.aspx.

Q. We have black raspberries at my mom's and would like to move them. When and what type of prep do I need to do to the ground for them? They have been there for over 50 years and I would like to keep them; they are not as many as there were and I need some help.

A. Moving a 50-year-old planting of any species is likely to be a formidable, if not unwise, task. However, the good news is that black raspberries are easily propagated by tip layering, and, in fact, that is something they do quite naturally on their own. To tip layer, dig a small hole several inches deep, then insert the tip of a current season's shoot or cane and fill around it with soil. The tip will soon grow upward, while the bend of the stem that stays in the soil will grow roots. In early spring, you can sever the newly rooted plant from the original cane and transplant to the new location. You'll find more information on raising raspberries at http://www.hort.purdue.edu/ext/HO-44.pdf.

Q. I planted this cherry tree approximately 10 years ago. Is the green growth (lichens?) on this cherry tree harming it?

sapling with scaly growth on it

A. Your photo shows some bark damage and a large colony of lichens, but they are not the cause of the bark damage. Lichens are harmless symbiotic organisms composed of a combination of fungi and either algae or cyanobacteria. Together, they live as one organism and are only using the bark of your tree for anchorage; lichens are not parasites. More information on lichens can be found at http://www.ppdl.purdue.edu/ppdl/weeklypics/1-12-04.html.

Q. I have a plum tree that has much fruit growing on it and then all the fruit prematurely drops off. Also, the graft was planted and has rooted, sending out shoots of growth so that it looks like two trees in one. Is there anything I can do to rescue this tree?

A. Most plums require two compatible cultivars for cross-pollination. When compatible pollen is not available, the ovaries of the flowers, which appear as small fruits, will abort and fall from the tree. If you know the cultivar of your tree, you can select a compatible cultivar from using this Purdue Extension publication on Pollination of Fruits and Nuts http://www.hort.purdue.edu/ext/ho-174.pdf.

It sounds like perhaps your tree was planted a bit too deep if the grafted portion is rooting. But I wonder if you mean that the rootstock is sending out shoots? In fruit trees, a particular cultivar known for desirable fruiting traits is typically grafted to a different cultivar or seedling rootstock in order to gain winter hardiness, disease resistance and/or dwarfing of the overall tree size. So you want to be sure that the grafted top produces only shoot growth, and that the rootstock only produces root growth. If the rootstock is sending up shoots (called suckers), they are usually quite vigorous and can quickly take over the planting if left unchecked. Remove these shoots completely back to the ground. If the graft is planting so deeply that the top is able to root, it is more difficult to address. If at all feasible, you could dig up the tree and replant at a more appropriate depth, or perhaps excavate near the trunk carefully and cut the roots that are growing from above the graft.

 

 

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox,