MIMOSAS AND DAYLILIES

by Curtis Smith, Ph.D.  

Q. Please tell me how to take a cutting from a mimosa. I have tried a few times and failed. The mimosa has yellow flowers at the moment and is about 30-feet tall.
via internet

A. This is a difficult question to answer because I am not sure which plant we are discussing. Here in New Mexico (I suspect you are not writing from New Mexico) mimosa refers to a tree with pink flowers. This mimosa is in the genus Albizzia. It is difficult to propagate from stem cuttings and is usually grown from seed. There is a true mimosa, Mimosa pudica, which is a smaller plant grown as a houseplant. It also has pink or purple flowers and is known as the "Sensitive Plant." The yellow flowers you describe indicate you are discussing neither the Albizzia, nor the Mimosa with which I am familiar. I will fall back on some basic plant propagation principles that may or may not help in this case, but these are guidelines for things to try when other techniques fail.

1. When you try to propagate a difficult-to-propagate plant from cuttings, use a rooting hormone (an auxin).

2. Take the cuttings from the base of the tree, or use sprouts that may develop from the roots. These often have a greater capacity for forming roots.

3. Attempt to propagate in different seasons. The reproductive season, when flowering, is often not a good time. Take softwood cuttings (when the new growth is still tender), semi-hardwood cuttings (as the growth begins to toughen), and hardwood cutting (after growth is matured and has become woody). This may be done at the beginning of a dormant season (when growth has matured and no new growth is being produced) or at the end of the dormant season (just before new growth begins).

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Q. Is it too late to move daylilies after they have started growing? They are being crowded by shrub overgrowth, but I forgot to move them during the winter?
Keith D.
Artesia

A. Daylilies are an excellent plant because they are tolerant of many conditions, including transplanting when growing. This makes them excellent landscape plants for New Mexico, and they also produce many beautiful flowers. Moving them now should cause little problem for the plants. You may lose this year's blossoms, but as tolerant as they are, I think they may bloom anyway.

Their current location, where they are crowded by shrubs, competing for light, water, and nutrients will also have a negative impact on their growth and flowering. Moving them will be the best long-term strategy. As you move them, you have an opportunity to thin them and to prepare the planting bed for the growth of the daylilies over a period of several years. Loosen the soil as deeply as possible, incorporate well-decomposed compost and phosphate fertilizer, and the daylilies should grow and blossom profusely for several years before you need to thin them again.

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Q. I have 3 very large mature pine trees that are fairly close to each other. The trees are sapping quite a bit. Is there anything I can do to slow down the sapping? Can I treat with a systemic labeled for insect, disease, etc.? Will pruning help?
C.
Albuquerque

A. The term "sapping" has several interpretations. It may refer to a fine mist of material "raining" from the tree and coating objects under the tree. It may also refer to clear pitch running down the trunk or to masses of cloudy pitch on the trunk. Each of these is a symptom of a different circumstance.

The "raining" of sap is probably honeydew excreted by aphids feeding on the twigs and needles. This honeydew is a syrupy substance. The aphids may be treated with any of several insecticides labeled for controlling aphids on ornamental trees. However, you will probably need to hire a licensed pesticide applicator to apply the insecticides. This is a case where the systemic insecticides may also be used. There is concern that some methods of systemic insecticide injection into the tree trunk cause damage to the cambium of the tree. Some pesticide applicators disagree with this assertion. Soil-applied systemic insecticides avoid this problem as does foliar spray application. The application of the foliar spray is difficult when treating large trees because it is necessary to control drifting of the insecticide onto adjacent properties.

Clear pitch on the trunk is not a cause for concern. This may be the result of bark cracking as the tree grows or as it sways in the wind. This pitch is the tree's method of closing the wound and is not a problem. Pruning can also be a source of this type of pitch flow.

The masses of cloudy pitch may indicate infestation by pitch or bark moth larvae. Both of these moth larvae do only minor damage to the tree. They are not active at this time of year, so they are not harming the tree now. Because they inhabit the pitch, it is difficult to effectively treat them with insecticides. Because their damage is mostly cosmetic, treatment is not recommended.

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Q. Last year the birds ate every blossom on our pear tree. The blossoms are ready to burst into bloom. What can I do to save them this year?
David G.

A. It is frustrating when birds damage the fruit on our trees, but especially frustrating when they eat the flowers long before they become fruit. However, the same tactics used to protect fruit may be employed to protect the flowers. The degree of success is often variable - sometimes good, sometimes a failure.

One of the most common techniques for protecting fruit (and flowers) is to use netting to keep the birds away. Of course, the birds will reach through the netting and eat some flowers, but flowers further in the tree should be protected. When using netting, it is important to extend the netting to the ground and anchor it well or tie it loosely around the trunk. If there are gaps, the birds will often get in and once trapped inside, they will do even greater damage.

Another, sometimes successful, strategy is the use of "fright." Many types of birds are easily startled and avoid places and conditions which are startling. That is the reason for the old "pie pan" technique. Aluminum pie pans tied to branches in the tree will twist and swing in the breeze. As they move, they will flash light in different directions. Flashing light will often discourage birds from approaching. At night this is less effective, but most birds are less active at night. The sound made by aluminum pie pans as they swing around and bump into branches is also a deterrent to birds. Unfortunately, it may be a deterrent to your peaceful sleep at night.

If so, a similar technique involves wrapping the tree with monofilament fishing line in the same manner that you would wrap strands of garland around a Christmas tree. The line should be strung in bands about a foot apart. As a bird flies toward a tree, it enters a zone in which the monofilament line has reflected or refracted light, then passing through that zone the light disappears. To the birds it seems like there has been a flash of light in the tree. Many birds will turn away at that time. Another variation is to hang one-to-two-inch strips of aluminum foil from the branches. The foil will not make as much noise as the pie pans but will spin and swing in the wind, creating flashes of light. The strips of foil are easier for you to see and remove at a later date than the fishing line.

Please remember that the birds are generally beneficial, just a nuisance when competing with us for fruit (in the flower or fruit stage). It is illegal to harm many song birds which may be the culprits so use discouragement techniques, don't harm the birds. You might also try creating a diversion by putting water and birdseed in another part of the landscape to attract the birds away from the pear tree. Of course, that may just invite even more birds into the vicinity of the pear tree and can work against you. Try it, however; it may be enough to reduce the damage to a tolerable level.

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Q. I have a Honey Locust tree about 30 feet from my house. About 15 years ago I had broken a section of cement out of our basement to put in a bathroom and dug out smaller-sized roots that came from that tree. We've developed some cracks in the foundation across from where the tree is located. Recently the cracks have gotten bigger. We have a brick and stucco home. Could the tree roots be the cause? How far and deep from the tree trunk do the roots grow? The tree is about 50 years old.
James P.

A. If there is sufficient water around the foundation of the house to encourage roots to grow there, it is possible that the roots growing next to the foundation are enlarging and stressing the foundation. However, here in New Mexico with our very dry climate, such a situation is usually caused by our watering a flower bed next to the foundation. Since you indicate that the tree's roots were present next to the foundation 15 years ago, it is likely that they are still there and have enlarged over time. As roots enlarge, they can slowly exert great pressure. However, I wouldn't expect a lot of damage from the roots unless the concrete wall of the basement was not reinforced or unless it was quite thin.

Regarding the location of roots, roots can grow three or more times the height of the tree from the tree, so they are certainly able to reach your foundation. However, the thick roots tend to be near the trunk, tapering rapidly with distance. The distance of the tree from your home (30 feet) also suggests that the roots are not major culprits. At that distance the roots should have tapered to a smaller size which would not be as damaging. It is often reported that 95 percent of tree roots are in the top 3 feet of soil, and 90 percent in the top foot. There are deeper roots, but relatively few roots below the depths described above. This also provides evidence acquitting the roots as likely culprits.

I prefer to recommend that flower beds and other plantings be kept a couple of feet from the foundation and that water be diverted from soil near the foundation. In our dry climate, that will discourage growth of roots at the foundation and may have some beneficial effect in discouraging termites, as termites, like roots, thrive in moist soil.

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Send your gardening questions to:
Yard and Garden, ATTN: Dr. Curtis Smith
NMSU Cooperative Extension Service
9301 Indian School Road, NE, Suite 112
Albuquerque, NM 87112

Curtis W. Smith, Ph.D., is a an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. Dr. Smith and Dr. George Dickerson host Southwest Yard & Garden, a weekly program for gardeners in the Southwest. It airs on KRWG in Las Cruces Saturdays at 11:30 a.m., repeating Thursdays at 1 p.m.; on KENW in Portales on Saturdays at 10 a.m.; and on KNME in Albuquerque on Saturdays at 9:30 a.m.