Some fall and winter crops can be planted now in Las Vegas

A: I posted a calendar for planting in the fall on my blog. Download a copy there but I will give you a rundown of the crops which are normally started this time of year in the eastern Mojave Desert.

First, some background. There are two planting times each year. Plant cool season vegetables and herbs that withstand frost and cold during the late summer, fall, winter and spring months. Plant the warm season, winter-tender vegetables and herbs when danger of frost has passed and into the midsummer months. Warm season crops die or perform poorly during cold or freezing weather.

Even though it’s still hot now, this is the time of year to plant several fall and winter crops. Notice that I said many, not all. Exact planting dates vary with soil and air temperatures, the time plants require before they are ready to harvest as well as the quality of the end product.

Cool season crops that require 60 or more days before harvesting will be just fine if planted now. It is too early to plant crops such as radishes, which are ready to harvest in 30 days.

Exact planting dates vary with your garden microclimate. Gardens located in warm microclimates have different planting dates from those gardens in cooler microclimates. If you are lucky enough to have a landscape with more than one microclimate, you can stagger your planting dates so that the same crops mature a few days or even a week or two apart.

Plant gardens that face west or south later in the fall but earlier in the spring. Gardens facing east or north are planted in the reverse order.

The following vegetables can be planted during September from seed or seed pieces for fall, winter and spring harvest: beets, broccoli, carrots, collards, endive, Irish potatoes, kale, kohlrabi, lettuce, peas, rutabagas, spinach and Swiss chard.

The following could be planted as small transplants: broccoli, Brussels sprouts, cauliflower, cabbage, celery and Chinese cabbage. If temperatures are unusually hot, delay putting in transplants until weather cools off a bit.

Mulch the soil to keep the seeds and roots of transplants moist and cool. Mulching will improve the germination of seeds and establishment of transplants.

Q: My hibiscus plant, transplanted from a pot to my outdoor flower bed, is blooming like it should. But the leaves are not getting any bigger than 1 to 1½ inches long and ¾ inch wide. The new leaves also only get to that size. I water and fertilize if with Miracle Grow regularly, but that does not help. Any suggestions?

A: Because we are in a desert, hibiscus will not look similar to those grown in semitropical or tropical climates, but we can approach that look if we are careful where we plant it. Leaves growing under high light intensities of our desert, provided they are getting enough water and nutrients, will be dark green, smaller, thicker or tougher and develop a thick waxy coating on the leaf surface.

The same plant growing under lower light intensities of wet and cloudy climates will have larger and thinner leaves with a waxy coating that is not as thick. The same plant growing under the dense canopy of the tree will become “leggy” with large distances between leaves and thin stems that will not support its own weight.

Compost mixed into the soil at the time of planting and applied annually to the soil surface surrounding the plant encourages larger and healthier leaves. Apply about 1 inch of compost to the surface of the soil surrounding the tree. Scratch it into the soil surface as much as you can without damaging roots too much.

After you have finished, apply a second layer of compost to the surface of the soil and water it in thoroughly with a hose. Each year apply a 1 inch layer of compost beneath the plant and water it in. Hibiscus will benefit from 3 to 4 inches of wood chips applied to the soil surface.

An abundance of nitrogen fertilizer will encourage larger dark green leaves, particularly when combined with applications compost. Phosphorus is important for flowering but it does not need to be applied as often as nitrogen.

In your case make sure nitrogen is applied regularly through the growing season to maintain dark green color and “push” new growth. Combined with moderate amounts of shade, nitrogen will encourage more leaves and leaves that are larger.

In short, planting on the east or north side of a building, combined with annual applications of compost, fertilizer and regular deep watering will maximize the leaf size of your hibiscus in a desert climate.

Q: I have had this palm for 10 years. Every time I add additional water with a hose or bucket I lose more fronds. Every year I cut higher on the palm to get rid of dead fronds. I drove a metal stake down 18 inches but did not pick up any visible moisture in three different places. Any ideas on how I can go about this from a more scientific method?

A: I did not see a whole lot wrong with your palm in the picture you sent to me. It is pretty normal for the fronds to begin to brown out and start to die once they drop below horizontal.

In our climate, it is also pretty common to have some tip burn on the leaves along the fronds, particularly as they get older and drop close or below horizontal.

I did notice you have Aptenia, hearts and flowers, growing at the base of the palm. This plant is not complementary to a palm that has deeper roots. Aptenia has shallow roots so it is watered frequently with a small amount of water. Palms must be watered more deeply and less often.

If you are going to plant something at the base of a palm, plant something with deeper roots that has a similar watering requirement. Replant at the base of the palm with something more deep-rooted that can give you some color.

Select a woody perennial that give you season-long color in that spot or an evergreen with a deep root and a similar requirement for water.

Q: I had an old peach tree of about 30 years die. We cut it down and had it removed. Last year several suckers sprouted from below the ground. They have different leaves so I know it is not peach. What are they? Should I leave them alone and allow them to grow?

A: Having a 30-year-old peach tree is quite an accomplishment. They are normally a short-lived tree as far as fruit trees go. Peach is hit very hard by borers and may start to decline around 12 to 15 years of age. A 20-year-old tree is really getting up there in age.

When you purchase a peach tree from a nursery it is grafted (budded) onto a different tree called the rootstock. Basically, there are two different trees joined together; one is grown for its fruit and the other is grown for its roots.

Frequently, the tree selected for its roots does not produce particularly good fruit. That is not the reason it was selected. It was selected because its roots had some particular quality that was desirable for the entire tree.

Remove these suckers from the base of the tree. They will grow but the fruit produced will be low quality compared to the peaches that you enjoyed for so many years.

— Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.