WORK WITH YOUR SOIL (Nov. 23, 2008)

Garden soils range from lean, rocky or sandy soils with low nutrient values to heavy, nutrient-rich soils with poor drainage. Although many common garden plants prefer loamy soil with good drainage, we strongly recommend working with the soil you have by selecting appropriate native plants that are adapted to your natural conditions.

Amending soil can be difficult and if done improperly can worsen garden conditions. For example, adding small amounts of fine grained sand to clay soil exacerbates poor drainage. The clay particles strongly adhere to the sand, in effect creating concrete. On the other hand, adding nutrients to sandy soil may temporarily enrich it, but rain and irrigation will quickly wash away these amendments. During periods of heavy rain these chemicals can find their way into storm drains, polluting our beaches and water ways.

Check our plant lists for suggestions on plants adapted to heavy soil or well-drained, sandy soil.

Can you give some other tips for successfully planting new trees?

A: Remember to plant your trees in the late fall to winter, giving them the maximum amount of time to grow new roots before the hot, dry summer arrives. You will need to provide year around irrigation for new trees through the first few years.

Remove nursery stakes when planting. If the tree needs staking for protection, loosely stake as described on the International Society of Arboriculture website (http://www.treesaregood.org/treecare/tree_planting.aspx). Allow the tree to sway so it will develop a strong flare and caliper.

A tree is an investment in the future. Choose carefully, and learn how to plant and care for your developing tree.

The leaves started drooping yesterday. My plant does not look good. Can it be saved?

A: The long heat wave this past July stressed plants as well as people, leading to numerous questions like this one. Water – either too much or too little – is a primary cause of death for garden plants. The way to tell whether your stressed plant needs water is to check the soil. If it is damp where the roots are, then the plant is probably suffering from over watering. Water is present but the plant can not take it up due to root damage. It looks thirsty and is thirsty, but this is due to too much water. These plants usually do not recover. The only thing you can do is cut the water, let the soil dry out and see what happens.

If the soil is dry and the plant perks up when watered, it was thirsty due to too little water. Water deeply and hope it was not too stressed to recover. The Concha ceanothus in my yard suddenly turned a sickly yellow. The soil was dry so I watered it. Alas, it was too late and the plant did not recover. I have removed it and plan to try again, planting in the late fall.

Young plants, those not yet established, are most vulnerable during severe weather. Their small size and undeveloped root systems make it hard for them to survive weeks of extreme heat. Water and hot soil often lead to root rot. So it seems that watering is bad and withholding water is bad. Observing your plants carefully – looking at the leaves, both old and young, and the buds - can tell you a lot about what they need. When old leaves turn yellow and drop, this may be due to senescence. It is common in sages, monkey flowers and some Ceanothus. When the younger leaves and buds dry up, you probably have a problem. If the whole plant wilts, you also are probably in trouble.

It is sad and expensive to lose plants. Still we must remember that a garden is an organic system. One of the reasons I enjoy gardening is the unpredictability and challenge of it. When a plant dies, it should be a learning experience. I try to figure out what went wrong. If I think I know why it died, and I can change the adverse conditions, I try it again. If I just don’t know, and I love the plant, I may try it again. If I lose a plant more than twice, it was not meant to be in my garden.

I try to be understanding when callers describe their garden losses. It may be helpful to know that even here at Rancho we have lost plants this hot summer. And as mentioned above, I have lost some in my own yard. When we make mistakes in life there can be serious consequences. When we make mistakes in our gardens, we can lose plants. But after all, it is only a plant!

Can I cut back my coyote brush to get rid its woody undergrowth?

A: Yes coyote brush (Baccharis pilularis) responds well to a severe “haircut.” At Rancho Santa Ana Botanic Garden we do this every few years to keep these plants looking their best. You can cut them nearly to the ground in the spring. Follow this with a dilute application of fertilizer and some water, and before you know it they will green up, looking better than ever.