Ask a Master Gardener

Q. My elm tree volunteer I took from a friend's yard about 12 years ago has been growing well at my house in Golden Valley until last year. In the spring it got a lot of seeds, but why didn't it get any new branches?

A. I'm going to assume this elm is not the Chinese elm that is more suited to the Kingman area but may be the American elm. The American elm typically is planted in cooler climates. It can grow in USDA Zones up to 9, which includes Golden Valley, but it may not do as well.

My first thought is improper watering and/or a problem with the roots, since it has done well up until recently. The roots extend 1.5 to 4 times the canopy of the tree when established. Eighty percent of the roots are in about the top two feet of soil. The roots may be stymied by caliche (a crust of calcium carbonate under the soil in arid climates) and cannot send nutrients up into the tree for new growth. Deep watering is essential to a tree's health. Water past the canopy down two feet and apply infrequently. In the winter this may be once per month, the summer once per week. It is difficult to be specific about irrigation with varying soil types and watering methods, so measuring moisture depth in the soil is recommended. These guidelines are generally applicable for most trees, including fruit trees.

Other possible reasons your tree isn't thriving:

• It could be the tree is planted in grass and not getting deep watered;

• It is getting older to the point where our hot climate is creating stress;

• It is in declining health because of dutch elm disease (a fungus spread by elm bark beetles), it needs nitrogen or is being invaded by insects.

Q. How can I make a compost pile and what is it good for?

A. A compost pile is a great way to get rid of your kitchen scraps, dead leaves or brown material (dead plant materials, etc.) you have lying around your yard and keep it out of the landfill. Compost helps retain water in the soil, has a lot of very good nutrients for your plants, trees and bushes, and is simply marvelous for your vegetable garden. It also neutralizes the alkalinity of the desert soil.

A compost pile is very easy to make. Find a spot to put your materials where they won't be impacted by anyone or any animals. It needs to be near a water source as well. You can purchase a bin that rotates or you can build one yourself. You can put together a ring of heavy mesh wire, some old pallets, concrete blocks or an unused small dog kennel. It's important to be able to get to it to turn your pile frequently.

Start by adding green materials and brown materials. For the best mix, use 4 parts of brown material (carbon) to 1 part green material (nitrogen). This can vary up to a 50/50 mix, but it is recommended not to use more than 50% green material. Brown (carbon-rich) materials include straw, shredded newspaper, dry plant materials (i.e., trimmings, leaves, vines), dry grass clippings and small branches. Green (nitrogen-rich) materials include a variety of barnyard manures and beddings (as long as it doesn't contain Bermuda grass), wet grass trimmings, vegetable and fruit peelings and parts, alfalfa hay (also pellets), tea bags, coffee grinds and filters.

Do not compost meats, grease, fats and oils, dairy products, dog and cat feces, Bermuda grass or diseased plants, and also be sure to avoid poisonous plants such as oleander, eucalyptus and salt cedar (these contain toxins that inhibit plant growth).

A 3-foot by 3-foot by 3-foot pile is ideal. Shred or chop all ingredients to be put into the pile. Smaller pieces are better for maximum breakdown. Add 4 parts of brown material to 1 part green material layering alternately. Sprinkle in soil occasionally and make sure to cover the food waste with plenty of brown material. Sprinkle each layer with water, making it like a wrung out sponge. You can tarp the pile if heavy rains occur.

As decomposition occurs, the pile will heat up. The interior can be as high as 165 degrees and can be checked by putting your hand into the pile or inserting a thermometer. Use a pitchfork to thoroughly mix the pile from time to time before it cools down.

More water and green material can be added at this time. The more you mix your pile, the faster your pile will decompose. It can be ready in as little as 2 or 3 months. Keep repeating these steps until the mixture is soft, dark and crumbly and has a very earthy smell. This is what they call black gold. A half-inch screen can be used to sift the final compost to remove larger pieces. They can be returned to the bin for further breakdown.

Q. After our last big arctic freeze my bushes and plants look like they're dead. Should I cut off the dead branches and leaves or just pull the plant out altogether?

A. Some plants are very resilient and even though they look absolutely dead as a doornail, they may have survived. If you pull the plant out of the ground, there will never be a chance of it coming back. It's a wait-and-see game until the spring. Water your plant occasionally when the weather has warmed up a bit and see what happens.

Resist your impulse to trim off the branches or leaves that look dead. These parts, although seemingly dead, can still be a help to the rest of the plant. They can shield the plant from winds and further cold damage.

It's best to leave all the dead stuff on the plant until you are able to see that the plant is alive in the spring.

Another way to see if the plant or tree is still alive is to take a knife or your thumbnail and just scrape lightly on part of the branch. If it's green, your plant is still alive.

More in-depth information can be found at the University of Arizona Cooperative Extension online site: https://extension.arizona.edu/programs/urban-horticulture - "Dealing with Freeze-Damaged Landscape Plants" under Publications.

Q. Can I use fallen leaves from bushes and trees in my garden?

A. Yes, leaves work great when worked into the soil or as mulch on top of the soil in addition to adding to your compost pile as explained above. Dig leaves into your soil now for spring planting - any type of plant will benefit. Save your leaves (it's better if leaves are shredded) and apply about 4 inches to the top of the soil in warmer weather to keep roots cooler, reduce weeds and prevent evaporation. That evaporation prevention means the plant will need less watering.

Beware of winds blowing the leaves away if your garden is in an open area.

Whether you dig them into the soil or apply on top, leaves also provide nutrients requiring less fertilization.

Most of us have shady areas around our home. Leaves compost well when piled in these shady areas. It helps if the leaves are wet from rain or watering, and shred larger leaves.

The front corner of my house has high walls and faces north. It never gets any sun and as long as the leaves are moist, I get good compost in about 3 months during the winter.