Fall Tasks in the Garden

Some people wait all year for fall weather to arrive. The heat of summer is over and the tourists are gone along with that pesky fog along the coast. For us up here in the Santa Cruz mountains, this is one of the best times to be outside. Here are tips for early fall in the garden.

Late fall is not a good time for major pruning so if you have some shrubs that need a tune-up do it soon.  Wounds heal slowly later in the fall, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. Wait to prune most trees until late in the dormant season or in late spring after leaves and needles form. To avoid sap flow on birches and maples, prune after leaves mature. Fruit tree summer pruning should have already been done when growth ceased.

Refresh perennials, such as butterfly bush, salvia and yarrow by cutting a third to half of their growth later in the fall.

Rake leaves- compost or put in your green can. If large leaves are left in place they will mat down and set up fungal problems come spring.

Remove dead and diseased leaves from under camellias, rhododendrons and roses.

 

Bearded iris

Now through October, divide summer blooming perennials that are overgrown and not flowering well. Alstroemeria, agapanthus, coreopsis, iris, daylily, yarrow, rudbeckia, calla lily, aster and penstemon fall into this category. You can also divide spring blooming perennials like candytuft, columbine, astilbe, bergenia and bleeding heart although they don’t always bloom the first spring afterwards due to the energy they use re-establishing themselves. If you’re on a roll out in the garden, though, go for it now. You never know what other projects you may be working on next spring.

Start perennial flowers seeds now so that they will be mature enough to bloom next year.

Fertilize shrubs lightly one last time with an all-purpose organic fertilizer or layer of compost. Use compost only on California natives.

broccoli with sweet alyssum

Plant cool season veggie starts like broccoli, cabbage, cauliflower, chard, lettuce, spinach, brussels sprouts, onions and leeks in soil enriched with 4-6″ of compost as summer vegetable crops will have used up much of your soil’s nutrients.You can sow seeds of beets, carrots, radishes, spinach, arugula, mustard and peas directly in the ground. Planting early ensures your plants get a good start before cold weather sets in and growth mostly stops until spring. You’ll be able to start harvesting in just a couple months if you start now that the weather has started to cool.

If you aren’t going to grow vegetables in the garden this fall consider planting a cover crop like bell beans, fava beans and vetch after you’ve harvested your summer vegetables. Next month I’ll talk about how to go about doing this and how this benefits your soil.

Cut back berry vines that have produced fruit. Canes of the current season should be trained in their place.

Spider mites and thrips are especially prolific during the late summer. If some of the leaves on your plants are pale with stippling, spray the undersides of infected leaves with organics like insecticidal soap switching off with neem oil as they build up a resistance to one of the pesticides. Plan to spray with a horticultural oil in the winter to kill overwintering eggs.

Autumnal Equinox in the Garden

The autumnal equinox happens on Saturday, September 22nd this year. It’s the official start of fall when the sun crosses the celestial equator and moves southward. The earth’s axis of rotation is perpendicular to the line connecting the centers of the earth and the sun on this day. Many people believe that the earth experiences 12 hours each of day and night on the equinox. However, this is not exactly the case.

During the equinox, the length is nearly equal but not entirely because the day is slightly longer in places that are further away from the equator ( like where we live ). Also the sun takes longer to rise and set in these locations as it does not set straight down but in a horizontal direction.

ceanothus ‘Heart’s Desire’

With the changing of the season, take advantage of fall planting weather by looking at what’s covering your ground. Be it the small lawn for the kids to play on, ground cover to keep the weeds at bay or erosion control to keep the hillside intact, this is an excellent time to plan for winter.

Let’s start with the lawn. If you still need a space for recreation, this is a good time to reseed those bare spots. Also to keep the lawn healthy by removing underlying thatch with a thatching rake. Then aerate the lawn by poking holes in the sod and fertilize with a complete lawn fertilizer like an organic all-purpose. Your lawn needs the phosphorus in the fall to encourage deep, strong roots for the winter.

If the kids are grown and no one is using that lawn, why not rip out the water guzzling grass and replace it with a walk-on groundcover? There are many to choose from like dymondia, lippia, potentilla, duchesnea strawberry or any of the kinds of thyme.

Living ground covers add beauty to the garden while holding the soil in place and preventing erosion. They contribute to soil health by encouraging microorganisms. A garden wouldn’t thrive as well without groundcovers.

One of my favorites is Elfin thyme. It doesn’t need mowing, edging or fertilizing or much irrigation. You can walk on it and it stays green all winter, shading into bronze tones when the weather cools. It even blooms in midsummer for several weeks. Note that bees are attracted to it as with all of the ground covers in the thyme family at this time.

kurapia

Another favorite that I have in my own garden is kurapia. It’s deep rooted, doesn’t require much water, is compact and low maintenance. It’s been bred to have sterile seeds. This is a good groundcover if pollination of nearby fruit trees is needed or you want to encourage bees to your garden for pollination. If bees are an issue kurapia can be mowed to cut off the blooms.

There are also Ca. native and prairie meadow grasses that you can walk on. They need little irrigation and even less mowing. Some can be planted from seed, others from plugs or sod. Good choices include Idaho, California and red fescue, carex pansa, June grass and Hall’s bentgrass.

grevillea lanigera ‘Mt Tamboritha’

If you don’t need to walk on your groundcover, low-growing native shrubs that are good groundcovers are baccharis, ceanothus maritimus, ‘Anchor Bay or ‘Heart’s Desire’, manzanita, creeping snowberry, creeping mahonia, salvia ‘Bee’s Bliss’ and ribes viburnifolium. Mediterranean ground covers like cistus salviifolius, grevillea lanigera, rosemany prostratus, rubus pentalabous are also good low-water choices.

It’s time to enjoy fall weather and cover that ground before winter.

All About Mums

Can it be? Already I’m seeing my dogwood and crape myrtle showing signs of fall color. Pictures on Instagram and Facebook from other gardeners show early color on sumac and lilac. I know fall is in the air when the pink amaryllis belladonna bloom and I’m ready.

Garden mums

Mums are in their prime as early as September. We tend to think of chrysanthemums at Thanksgiving as temporary filler plants for fall containers and borders but mums are perennials and can play a bigger role in your garden if you let them. Established mums can tolerate quite a bit of neglect and still keep blooming every year.

Chrysanthemums were first cultivated in China as far back as the 15th century. Over 500 cultivars had been recored by the year 1630. In Japan records go back all the way back to the 8th century relating to mums.

The botanical name for the garden chrysanthemum has been changed to dendranthemum grandiflorum but I never hear anyone use this name. It doesn’t exactly roll off the tongue.

Yellow or white chrysanthemum flowers of the species. C. morifolium are boiled to make tea in some parts of Asia. In Korea, a rice wine is flavored with chrysanthemum flowers. Chrysanthemum leaves are steamed or boiled and used as greens in Chinese cuisine.

Another variety of chrysanthemum- cinerariaefolium- is important as a natural source of insecticide. The pyrethrins extracted attack the nervous system of all insects. Harmful to fish it should be used with caution but it’s not persistent in the environment and is biodegradable.

Grown for years to flower only in late summer and fall, they are short day plants, setting buds when they receive light for 10 hours and darkness for the other 14 hours of the day. This is why mums bloom in the spring on leggy stems if they are not cut back. And this is how growers manipulate their blooming, adjusting the dark and light periods with shades in the greenhouse so buds will form in any month. They’re nearly constantly available in grocery stores and florists in every season.

At this time of year when garden mums abound pick a plant with lots of buds. They bloom only once and won’t set more flowers until next year. Those buds, though, last a long time if you don’t let them dry out. Although mums are somewhat drought tolerant once established you should water deeply once or twice a week depending on the weather.

The specific type of plant doesn’t matter since they all have long term growth potential. If you particularly like one color or form of chrysanthemum, plant it now to enjoy again next year. You never know what the growers might decide to grow next season.

Choose a well-drained, sunny spot to plant them. Like many members of the aster family, mums won’t tolerate soggy ground. After blooming, trim off the old flowers and cut back plants to within a 4 or 5 inches of the ground. If you started with 4 inch pots, trim back by half.

Next spring pinch them back when they are 8 inches tall. Keep pinching until July, then allow plants to start forming buds for the traditional fall show.

A word of caution: all parts of chrysanthemum plants are potentially toxic to dogs, cats, humans and other mammals and a skin irritant for some people.

Fall Planting California Natives

The chill is in the air. At least as I write this. Next week it could return to summer-like weather but for now I’m thinking of what plants I want to add to my garden this fall planting season. California native plants are well suited to planting at this time of year and acclimating to their new homes without much stress. Here are some ideas to get you started.

matilija poppy

By planting from mid-September through mid-November, roots of all plants have a chance to grow during autumn and most of the winter as well without having to supply nourishment to the leafy portion of the plant. Roots of deciduous plants still grow even after plants drop their foliage as long as the ground temperature is above 50 degrees. Cooler day and night temperatures slowly harden off the top of the plant to prepare for the cold days of winter.

Another reason that fall is the no-fail planting season is because plants put in the ground in fall need less water to establish. The plants themselves use less water since photosynthesis is slowed by shorter days even if it’s occasionally hot. Evaporation rates slow down also during fall so moisture in the soil lasts longer as well. Sometimes we get lucky with fall and winter rains perfectly spaced so the ground never completely dries out. I’ve heard rumblings about an El Nino winter but you know how that sometimes goes here in our coastal area.

ribes sanguineum ‘King Edward VII’

Plants that thrive in dry, shady spots benefit especially from fall planting as they need established root systems before next years dry season. Dry shade sometimes occurs in places beyond the reach of the hose but also under native oaks. To protect their health, it’s a requirement that plants underneath thrive with little or no summer irrigation.

Plants of proven success under these conditions include native currants and gooseberry. Ribes sanguinem (red flowering currant) is a show stopper capable of controlling erosion. In the spring the long, flower clusters of this deciduous shrub will dominate your garden. There are many selections of this plant to choose from so if the huge white flowers appeal to you ‘White Icicle’ will be beautiful in your landscape. ‘Barrie Coate’ and ‘King Edward VII’ have spectacular deep red flower clusters and ‘’Spring Showers’’ has 8″ long pink ones. Grow in full sun to partial shade. This California native requires little water once established and is a valuable nectar source for hummingbirds.

Some other good California native shrubs for erosion control are western redbud, mountain mahogany, western mock orange, lemonade berry, toyon, snowberry, matilija poppy and western elderberry. ribes viburnifolium, creeping mahonia and snowberry, baccharis, ceanothus maritimus and Anchor Bay are good groundcover selections.

Smaller natives that put down deep roots are yarrow, coast aster, California fuchsia, wild grape, mimulus, buckwheat, wild rose, sage and salvia.

Bush poppy (dendromecon rigida) is another native found right here in our area and needs no irrigation at all once established. Beautiful bright yellow, poppy-like flowers cover the plant in spring. They can be propagated from cuttings taken in summer and are pest and disease free.

Remember when setting plants on a steep slope to arrange them in staggered rows. Make an individual terrace for each plant and create a basin or low spot behind each one ( not around the stem ) to catch water. Set the crowns of the plants high so they won’t become saturated and rot after watering and make sure mulch does not build up around the stem.