Smaller containers need to be watered more often

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Apricots, peaches and nectarines are now in full swing at the Master Gardener Orchard. Have you ever had fresh fruit right off of the tree? Come on out and learn how we do it. You might even want to take some fresh fruit home. For more information about the orchard and how to get there, call the Master Gardener Help Line at 257-5555.

Question: During the last two years I had nice red blooms this time of year on dwarf oleanders, but no second bloom. This year I had an outstanding crop of blooms. Does this species only bloom at the beginning of the season and not again?

Answer: The oleander has hundreds of different varieties, many more than the red, white, maroon and salmon colors we know. It has been under cultivation for more than 2,000 years and was distributed along the trade routes of Marco Polo.

Oleanders vary not only in flower color and size but also tolerance to freezing temperatures and how often they bloom. Shearing oleanders when they are actively growing will remove new growth where the flowers originate.

So, if you have not sheared this plant, it is possible that you may have a variety that blooms only in the spring and fall. Fertilize it, water it well, don't shear it and let me know if it blooms in midsummer.

Q: Please advise me as to a flowering vine suitable for container.

A: Any vine can be planted in a container. The more aggressive the vine is (larger it can grow such as trumpet vine) the larger the container needed. The less aggressive and smaller the vine (like star jasmine) the smaller the container can be. Eventually the vine will outgrow the container and need to be replaced or replanted into a larger container.

Smaller containers need to be watered more often and kept out of the direct sunlight where the soil in the container will cook the roots during the summer. Always water just prior to the heat of the day. Never let the container enter 100-plus temperatures dry.

Determine the size vine you need and what you want it to do then select the vine. I hesitate recommending plant materials since I am not sure what is available at your nursery.

Q: I e-mailed pictures to you of my pear tree. The leaves have black spots on them and I wanted to know what the problem might be. Thank you for your quick response. Although I have mulch around the tree at least 3 feet, I will remove as much rock from the south side of the tree as possible and replace with mulch to minimize the ground heat and especially the reflected heat.

A: Those of you who are getting my electronic newsletter can see these pictures. E-mail me at morrisr@unr.edu if you would like to subscribe.

I do not see a disease problem. To me it looks like heat damage or stress. You have a lot of heat coming off of that rock mulch I see in the picture and it is probably just a very hot location. Pears are not great for real hot locations and will scorch. The leaves otherwise look healthy. I am not sure there is much you can do to correct that and the problem may get worse as temperatures rise.

It is possible that they either are getting watered too much or not enough, and/or watered too often or not often enough, and the symptoms can be similar to this. As small trees right now they should be getting 20 to 30 gallons at each watering and completely wetting the area under the canopy.

If this is drip they should have a minimum of four emitters under the canopy about 12 to 18 inches from the trunk in a square pattern. I would think you would be watering perhaps three times a week in that location and with rock mulch. Hopefully they were planted with compost in the hole.

Q: As a fairly new Vegas resident, when is the best time to dethatch and aerate my lawn?

A: Lawn aeration can be done any time of the year and it will benefit from it. However, if you have the luxury of picking a time to aerate, the best time is just prior to hot weather, perhaps March and April.

Lawn aeration helps get grass plant's roots deep and improves their tolerance to heat and drought. After you aerate, follow-up with a fertilizer high in phosphorus to stimulate root production.

Dethatching is best done in the fall with enough time for the grass to recover. Timing for this would be best in late September and October. Spring dethatching opens up the lawn too much and allows spring weed invasion. Dethatching should not be done when it's hot or in midwinter.

Q: My lawn has a large, very dry, yellow, brittle patch in the middle. Next to it is a small bare patch, where the ground can be seen. I have only a small area that you could call green. I follow the watering regulations. I was told it was a lawn fungus.

It started out the season like it would turn green. But when the temps rose, the green stopped. I had this problem last year but I didn't lose the lawn. It stayed barely green. This year, I think I'm losing the battle because it looks like the big, dangerous spot in the middle is spreading.

It has not been aerated or fertilized in at least 4 or 5 years. It is mowed weekly, but I can't tell you any more details about mowing. Do you think my lawn can be saved?

A: Leaving the fertilizer out of the picture for the moment, the usual problem you are describing is due to an inadequately designed irrigation system or not scheduling your irrigation correctly. I do not believe that it is due to fungus disease problems this time of year.

I realize you were following a guideline for irrigation, but that is all that it is, a guideline. We went through some pretty hot and windy days early this year. These hot and dry days were not part of our typical weather history and outside of most guidelines.

When we get weather that is hotter or windier than normal, we have to bump our irrigation schedule up temporarily to compensate for that bump in our weather. When it cools off, we can return back to our guidelines.

Another problem can be due to an irrigation system that was not designed or maintained well. If the irrigation system was designed poorly, you will see "weak" areas of the lawn in the same spot year after year. These can be somewhere between irrigation sprinkler heads or in some cases right in front of them. It varies due to pressure and distribution problems.

A simple way to tell if it is due to water is when you see these spots developing, use a long screwdriver and probe into the soil and see if it is wet or dry compared to the greener areas. A screwdriver will be hard to push into dry areas. You can increase the irrigation amount, but if it is a poorly designed irrigation system, you are wasting water.

These dry areas also may be elevated areas of the lawn. If they are, then rent an aerator and aerate the lawn to get better water penetration into the dry areas. Water will run off of high spots and accumulate in low spots. This translates into green low spots and brown high areas.

A temporary solution, until you can aerate, might be to take a bucket of water and add some liquid detergent to it and pour it slowly over the wetted brown area. The liquid detergent will help temporarily get water into the soil instead of run off to low spots until you can get the problem fixed with a more permanent solution.

If you want a decent lawn then it needs to be fertilized on a regular basis with a good quality lawn fertilizer. It may be that you need to transition your lawn into a desert style landscape which is lower maintenance. Grass is easy to convert over.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension.