Is that plant dead? Should I replace it now? Tips for Fall planting

Mother Nature plants in the Fall and so should you.  Instead, however, of simply deciding which trees, shrubs or perennials to add to your arid garden this Fall, you may be looking at which plants you need to replace. The record-breaking heat in the Southwest and California (and Australia!) this last summer baked the leaves on many plants and turned them brown  overnight. On others the leaves simply fell off the branches. The plants appeared dead.

But don’t yank these sunburned plants out of your garden yet, especially now that the rains have come. Wait two or three weeks. The roots of dead-looking plants may have survived the heat and be ready to regrow.

If, however, you decide to replace some plants, consider the suitability of the ones you choose for replacements. The heat this last summer will probably be back next year and for many summers to come.  You may want to select more desert-like plants or take steps now to create micro-climates for parts of your garden that suffered most from the heat by adding shade-producing and heat-reducing plants.  And, unlike the Beanstalk of Jack-and-the-Beanstalk fame, the plants to create micro-climates don’t grow sky high overnight. Planting them this Fall–rather than waiting until Spring–will give them a head start on growth over the winter.

Plant now to create micro-climates in your garden

For starters you can help cool off your entire garden by planting a fast-growing hedge in front of a hot wall. This can be effective with both cement block walls around your property and  the stucco walls of your home. The shrubs’ leaves will block the sun from heating up the wall during the day so there will not be as much drying heat to be released after dark.  Overall your garden will feel cooler and a bit less dry.  And a cooler, slightly damper garden is better for all plants — and people.

Two drastically different hedge plants that grow fast are Pampas Grass (Cortaderia selloana) and Japanese privet (Ligustrum japonicum).

Pampas grass is close to being a Jack-and-the-Beanstalk plant. It will shoot up to as tall as 20 feet in one year, and should be cut back to 18 inches high in mid-winter.  But be aware: its blades have rough edges that can cut skin so wear gloves when cutting it back. And it may be very difficult to remove if you change your mind later. It is definitely a statement plant.

The Japanese privet is more ordinary looking–just a basic green hedge.  It grows about two feet a year, however, and is quite drought tolerant. Poor soil conditions do not seem to bother it either. In Spring it is covered with white flowers that look almost like lilac blooms, but don’t smell nearly as nice as lilacs. You can see these and other shrubs for hedges in arid gardens here.

Planting a tree for more shade is another way to create a micro-climate to help other plants in your garden survive in hot weather.

One rapid growing tree that is suitable for arid gardens is the Chitalpa (Chitalpa tashkentensis) which will grow about 3 feet a year to a maximum height of 25 feet.  It is a hybrid of the Desert Willow and the Catalpa tree that was created specifically to thrive in hot, dry climates.  While it likes balanced soil, slightly alkaline conditions will not impair its growth. I especially like it because it has long-lasting, pretty pink-white blossoms, an open branch structure and provides dappled shade, rather than dark shade. You can see other trees for hot, dry gardens here.

The right way to plant a tree or shrub

The hole for planting should be 2 1/2 times as wide as the root ball, but do not make it deeper than the root ball.  The crown (the part where the roots meet the trunk or main stem) should be at or slightly above ground level–not submerged in the hole.  Be sure to add a lot of rich organic mulch into and around the hole you dig for a new tree or shrub to provide nutrients for growth, especially root growth during winter.  Really soak the soil with water around the planting hole and, once planted, water the tree regularly until the plant is established.

Now here is one last recommendation for coping with our hotter, drier summers and the damage of relentless heat. In my last post I wrote about applying organic mulch around plants, trees,  and in flower beds to help supply nutrition. Another benefit of mulching  is that mulch provides an insulating layer to protect the roots from scorching summer heat and winter cold.  That’s right — winter cold and its potentially damaging effect on plants is right ahead of us now. More about this in an upcoming post.

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