Fall Planting Tips

Autumn is the best time to plant California native perennials, shrubs, bulbs and wildflower seeds.

Since native plants have spent generations adapting to local growing conditions, they are great additions to home landscapes—and one that can save you time and resources. Native plants are rarely invasive. They support local wildlife—birds and butterflies depend on them for food shelter and nesting. And most of all they are beautiful.

Before heading out to buy plants, take a couple moments to examine your garden soil. A little preparation before you go can help you choose the best plants for your garden—saving you time and money!

  • A simple feel test can provide a good estimation of the soil’s physical structure.
  • Get your hands dirty and test your soil’s texture.
  • A more accurate sample will be collected about six inches below the surface.
  • The ratio of sand, silt and clay in soil determine its ability to hold moisture and nutrients.
  • A percolation test offers insight to how well your soil drains.
  • A simple DIY kit available in most garden stores can tell you what nutrients are present and if the soil is acidic or alkaline. 
  • Remember, the goal is to match the right plant to the right place. Many California natives plants grow in fast-draining, nutrient-poor soils.

Gardeners will find plenty of inspiration at the Fall Planting Festival at Grow Native Nursery Claremont. Shop thousands of beautiful plants and water-wise solutions for your home landscape and get advice from horticulture experts.

Garden admission is never necessary to visit the nursery and parking is free for all visitors.


Non-native Plants in your Garden

Although most non-native plants do not become invasive, millions of dollars are spent each year in California to control and mitigate the damage done by invasives. Many of these problem plants entered agricultural and wild lands from our own gardens. Among the culprits are fountain grass, periwinkle or vinca, English and Algerian ivy, French and Spanish broom and pampas grass. According to the Nature Conservancy the state of California spends more than $84 milion on controlling invasive plants annually.

It is not always possible to know which non-native plants will become invasive weeds. In fact, years can pass before an exotic starts to muscle its way into open space. Educate yourself on which plants to avoid by visiting the California Invasive Plant Council’s (Ca-IPC) informative website (http://www.cal-ipc.org/ ). Do your part to help by gardening with beautiful and interesting native plants. With over 5,000 species to choose from, there is an appropriate plant for every gardening situation.

Spring Maintenance

Most of your planting, especially of chaparral/scrubland shrubs and trees, should be done during the winter. Perennials, grasses, and riparian (water-loving) plants can be planted in the spring, though you will have more success planting during the cool, wet season. Gardeners in moderate, coastal areas can extend the planting season into the spring, though again working with our seasonal weather pattern is preferred.

Pay attention to new plants as they become established in your garden. Some will need supplemental water all year for about two years. Pinch back fast growing shrubs to encourage dense growth. This is particularly important for young sages (Salvia spp.). Excessive new growth can lead to weak structure, and the succulent growth is enjoyed by aphids. Prune and dispose of heavily infested stems. This problem usually resolves itself when ladybugs start to feast on the juicy aphids, and when the plant’s growth rate slows as summer approaches.

Cut back some spring and summer growing plants, such as coyote brush (Baccharis pilularis) and warm season grasses, deer grass (Muhlenbergia rigens). If you water and apply a dilute application of fertilizer these plants rebound quickly. Be conservative with the fertilizer to avoid excessive growth that requires pruning, and can be susceptible to stress from the summer heat and drought.

Many spring flowering shrubs, such as Ray Hartman wild lilac (Ceanothus ‘Ray Hartman’), can be pruned lightly after they bloom. New leaves grow on some of these plants above the flower stems. Prune the spent flower clusters to maintain a dense growth habit and eliminate these long bare stems.

Tidy up your garden. Remove weeds before they set seed. After you clean up weeds and spent wildflowers you can apply mulch to your garden to keep it neat and moderate soil temperatures. Inorganic mulch, such as decomposed granite, gravel, and rocks, is best suited for dry gardens with desert, chaparral, and scrub plants. Organic mulch is appropriate for woodland gardens.

Visit gardens, attend garden tours, chase the wildflowers and hike the San Gabriel Mountains to see the state’s remarkable flora in different settings. The most successful gardens take their clues from nature.

Transplanting Trees

Whether you are planting a native or non-native tree, it is best to transplant from a relatively small-sized container. There are several reasons for this. First of all, the longer a plant is in a container, the more time there has been for it to be abused. Container plants require careful irrigation. They can dry out quickly, or remain too moist while in pots. Their growth and general health can be badly impacted, even though they may not exhibit stress at the time of purchase.

A common nursery practice for larger trees is to trim lower branches and stake the young saplings so they have a tree-like form. This removal of low-growing, juvenile branches and staking of the single stem, diminishes the development of a flared, healthy caliper at the base (or crown) of the tree. Trees without this flare are more likely to become uprooted.

Some larger plants have been held in small containers for too long before being potted up. This can result in the roots wrapping around the pot. Again, the container plant may look fine, but as the plant grows, the twisted structure of its roots can result in death. This problem can be detected by a careful evaluation of the root ball at the time of planting.

Larger specimens are also more difficult to transplant. You have to dig a larger hole and carefully decant the specimen and place it in the hole. Soil around the plant must be compressed enough to eliminate large air pockets near the roots, yet not compacted so much that the roots are deprived of water and air. Proper planting is more difficult for larger specimens.

And finally, smaller pots are much less expensive than large boxes. Small trees become established more quickly than trees in larger pots or boxes, so not only is it more economical to start with a smaller size, it only takes a bit more patience and understanding.

So what size is the right size? If we are talking about an oak tree, acorn-size is probably the very best - with a few caveats. The first few years are slow - with little to show. Most people are not quite this patient, and prefer to have visible evidence of their magnificent, future shade tree. Second, acorn sprouts are especially tasty to squirrels and other critters, so without protection, many will disappear. Third, in many locations a small, young sapling may be vulnerable to vandalism or inadvertent damage.