I still have a few openings left in my landscape design class that begins Monday. This is a perfect Valentine's gift since the class is meant for couples. During a series of eight classes, this course will teach you how to design a desert landscape so that it will save water, reduce your energy bill, create outside living spaces and look great. You will leave the class with a finished landscape design.
The class meets in the evenings, twice a week at the University of Nevada Cooperative Extension Lifelong Learning Center, 8050 Paradise Road, near East Windmill Lane and the Las Vegas Beltway. For more information or to sign up, call the master gardener help line at 257-5555.
Q: A friend gave us some asparagus seeds to plant here in Nevada. We've pulled up information on the computer on how to plant them. Could you give us some information about when to plant?
A: Asparagus can be started from seed quite easily. The seed should be from a reliable source, not saved from fruits from the female plants of a friend. There are hybrid asparagus types out there such as UC 157 F1, which is a very good selection for the desert but will not come true from seed. So make sure you obtain the seed from a reliable source.
Seeds can be either started in a container, grown for a year and replanted as 1-year-old crowns discarding the female plants, or direct seeding in the garden. But the females still need to be discarded when they are determined. You will want to grow all male plants, if possible.
Seeds should be germinated starting about March. Crowns and seeds should be planted so that the permanent stand of asparagus has its crowns down about 10-12 inches deep. This will require preparing the seed bed 18 inches deep with plenty of old manure or compost rich in manure. You also will want to add phosphorus in the bed prior to planting.
The seeds can be spaced about 12 inches apart in the bed. The spacing can be multiple rows, 12 inches apart but with access for harvesting the spears so they are not damaged when harvesting.
Keep the beds about 3 feet so the spears can be accessed from outside the bed on kneeling boards. Keep your feet off of the beds so you do not compact the soil. Cover the seed with about 1 inch of compost.
Keep the seed bed moist and wait for thin, young spears to emerge. As they emerge, add your native soil that has been richly amended with compost so that the young spears still have a couple of inches above the soil level. They need to harvest light to continue to grow. Continue this until the soil level of the bed is at least level or slightly above the walkways.
You can harvest spears the first year provided the spears are at least the diameter of a pencil. Harvest for only six to eight weeks and let the rest of the spears continue to grow to maturity and fern out. Remove female asparagus plants as you see the berries develop and before they turn red and disperse seed. Do not cut back asparagus until at least December. You can cut them back even though they never turn totally brown here because we have relatively warm winters.
Q: I have a 2½-year-old Chilean mesquite tree. It was a small, double-trunk tree when we planted it. After a big wind a few weeks ago, the stakes broke and the tree split below the soil surface. We trimmed away a lot of branches to take off some weight and tried to prop it up. What I need to know is if there is something that can be put into the split to heal it and keep it from splitting more. My husband just wants to cut it down and plant another single-trunk mesquite in its place. I would love to try to save this tree if possible.
A: Thanks for the pictures. I think it is worth a shot. You can always remove it later if it does not work out.
The point of attachment, where the two trunks came together, is called a narrow crotch. The angle of attachment between the two trunks was too small, which did not allow for proper development of the trunk to support the weight. One of those main trunks should have been removed years ago so the remaining one would survive and support the weight of the canopy.
It looks like the trunk on the left side will have to be removed. Subscribers to my newsletter will see what I am talking about.
The remaining trunk is smaller than it should be to support the weight of the remaining canopy. This was because of the interference of its growth in diameter by the other, competing trunk. The remaining trunk should have its canopy reduced and thinned to take the stress off until it can gain some strength. Reducing and thinning the canopy will reduce the sail effect on the canopy due to the wind.
Reducing the canopy and thinning it should be done with some fairly aggressive cuts. Mesquite responds well to these types of cuts unlike some other trees, like ash. Hopefully the trunk will continue to increase in girth at the base and I think the tree will be all right.
The tree will heal itself from the damage. You don't need to apply anything. Just leave any wounds open for a few days after cutting and keep soil from touching it during the healing process. Make sure pruning equipment is clean and sanitized before making any cuts.
Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at firstname.lastname@example.org.