Category Archives: perennials

The Dog Days of Summer

They’re called the Dog Days of summer. You know those sultry days with the hottest summer temperatures. The Romans associated the hot weather between July 24th and August 24th with the star Sirius which they considered to be the “Dog Star” because it’s the brightest star in the constellation Canis Major (Large Dog). The Old Farmer’s Almanac uses slightly different dates but the Dog Days of summer are definitely here.

Dahlia- a repeat bloomer

Recently I moved to Bonny Doon where gardening in the hot, sandy soil is very different than the shady clay I was used to. One thing I’ve noticed is the existing drip system has not been modified to allow for the growth of the plants. The emitters which were originally placed at the base of each plant are not even close to covering the current size of the root zone. The crown of the plant is getting overwatered with each cycle but the rest of the plant is bone dry. Time to add more emitters maybe even downsizing to half gallon ones and moving them away from the middle of the plant. No sense wasting water that’s not doing the plant much good.

As summer rolls along you may become more aware of the different microclimates in your garden. With the drier and hotter weather this year some of your plants that used to get along just fine might be showing signs of stress. Taking note of these changes in the performance of your plants is what makes for a more successful landscape. When the weather cools towards the end of September you will want to move or eliminate those plants that aren’t thriving. Be sure to keep a thick layer of mulch on the soil around your plants to conserve that precious water you do allocate to each of your irrigation zones.

Roses with Baby’s Breath- deadhead regularly

The dog days of summer may be affecting our garden but it doesn’t have to stop us from being out in the garden. . The joy of gardening can take many forms including adding a wind chime, bird feeder or bird bath. Groom plants that need some cleanup. Many perennials benefit from a little haircut at this time of year to extend their blooming into the fall season. Santa Barbara daisies fall into this category. Lavenders will keep their compact shape by pruning a third of their branches now. This forces new growth in the center so the plant doesn’t get woody.

Deadhead flowering annuals and perennials as often as you can. Annuals like marigolds, petunias, zinnia and cosmos will stop blooming if you allow them to go to seed. The same is true of repeat blooming perennials like dahlia, scabiosa and lantana.

These plants know they’re on this earth to reproduce. If they get a chance to set seed, the show’s over- they’ve raised their family. Try to remove fading flowers regularly and you’ll be amply rewarded.

Strike it Rich rose

Fertilize shrubs lightly one last time in August or early September. All shrubs, especially broad-leaved evergreens such as rhododendron, pieris, camellia and lilac need to calm down, stop growing and harden off to get ready for the winter cold. Some plants have already set next year’s buds.

Roses will appreciate a bit of fertilizer now, encouraging them to bloom another round in September and October. To keep them blooming make a habit of pinching and pruning off old flowers. Always cut back to an outward facing branch-let with five leaves. There are hormones there that will cause a new rose to grow much sooner than if you cut to one with only three leaves.

Post Thanksgiving What-Not-To-Do List

Twas the weekend after Thanksgiving and all through the house, not a creature was stirring not even a gardener. I should probably do something productive, but what? Should I be good and do a little light weeding? Maybe I can muster up the energy to plant a few more bulbs. Come spring I’ll be happy I did. Then again I could make notes of my gardening successes and not so great horticultural decisions. “I know”, I say to myself, “this weekend I’ll revel in what I don’t have to do in the garden”.

Japanese maple in fall color

I don’t need to prune trees and shrubs at this time of year. Other than clipping a few well placed branches to use in a holiday wreath, I’m off the hook for this task right now. Deciduous trees are still in the process of losing their leaves and are not fully dormant. Evergreens shrubs and conifers can be trimmed lightly but most shaping is done when they start growing in late winter or very early spring.

The season is pretty much over for me except to enjoy what’s left of fall color and the ornamental grasses waving their seed heads in the wind. A lot of perennials are dying back but I’m not in a hurry to neaten things up. The seed heads left in the garden supply food for birds and other creatures while the foliage provides shelter for the plant in the cold and frost. Remove anything that has turned slimy or just plain unattractive but leave berries and seed heads for food and winter interest.

Purple finch

At this time of year my garden is visited mostly by chickadees, nuthatches, goldfinches, purple finches and warblers. They will spend the winter here and I’m doing them a big favor by not cutting back brown foliage containing nutrient-rich seed heads. Some of the reliable seed producers that I won’t have to clean up this weekend include artemisia, aster, coreopsis, penstemon, sedum, lupine, salvia, black-eye Susan, coneflower, phlomis, monarda, agapanthus and grasses.

Chickadees gather hundreds of seeds in fall and early winter and store them in hiding places to ensure themselves a food supply later in the season. They are a remarkable bird that we take for granted being so common. I read in Audubon magazine a couple years ago that a chickadee weighs about as much as a dozen paperclips but their body is large for their weight. This means they have to ramp up the number of hours they devote to feeding. At night chickadees cram themselves into tiny cavities and shiver, burning the day’s fuel to keep from freezing.

Anna’s hummingbirds at feeder

Hummingbirds still need a nectar source at this time of year. Anna’s hummingbirds live in this area all year long. So In addition to the plants in my garden that supply nectar I keep my feeders up year-round and keep them clean. They need your nectar even more in the winter when very little is in bloom. In addition to nectar rich natives like mahonia my abutilons are a winter favorite for them.

Other tasks I can put off at least for this weekend include planting wildflower seeds. I see California poppies coming up all over the place. Nature knows when the time is right. Well, maybe I’ll broadcast a few working them into the soil very lightly. I need to hoe off some early weeds that would compete with them. How many calories are burned in light gardening tasks? I might just reconsider not being a total couch potato this weekend.

Growing Chrysanthemums

It’s that time of year when every store I visit has mums for sale. Chrysanthemums are so common we often think of them as temporary filler plants in fall containers and borders. But mums are perennials and can play a bigger role in your garden if you let them.

Garden mums

Chrysanthemums were first cultivated in China as far back as the 15th century. Over 500 cultivars had been recored by the year 1630. There are records in Japan from the 8th century relating the 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. it is harmful to fish and should be used with caution but it’s not persistent in the environment and is biogradable.

Mums, black mondo grass, Blue Hokkaido squash

Grown for years to flower only in late summer and fall, chysanthemums 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.

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 don’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 whenever growth gets to 8 inches tall. Keep pinching until July, then allow plants to start forming buds for the traditional fall show. Mums need regular water so plant them in spots where you have other plants with the same water needs.

All parts of chrysanthemum plants are potentially toxic to dogs, cats, horses and other mammals. Ingesting the plants can cause vomiting, diarrhea, excessive salivating, rashes or lack of coordination, according to the University of California Davis School of Veterinary Medicine.

 

The Early Fall Garden To-Do List

The autumnal equinox happened September 22nd. 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.

Variegated alstroemeria

It was a hot summer and I’m ready for fall. This is the perfect time for transplanting or adding new plants to your garden. Why? Cooler air is kinder to plant foliage while soil temperatures are still warm creating an excellent environment for new root growth. In the fall many plants and trees, even broadleaf evergreens, are entering a period of dormancy. With no need to allocate resources into foliage, plants are transferring all their energy into roots and storing nutrients for the cool months ahead. By spring, the new root systems should be well established.

Now through October, divide summer blooming perennials like alstroemeria, agapanthus, coreopsis, iris, daylily, yarrow, rudbeckia, calla lily, aster and penstemon that are overgrown and not flowering well. 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. Start perennial flowers seeds now so that they will be mature enough to bloom next year.

bergenia cordifolia

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

Fertilizing roses now will encourage them to bloom again this fall. To keep roses blooming make a habit of pinching and pruning off old flowers. Always cut back to an outward facing branchlet with five leaves. There are hormones there that will cause a new flower bud to grow much sooner than if you cut to one with only three leaves.

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.

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

hemerocallis

Spider mites are especially prolific during the 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.

The weather these days is perfect for being outside. Enjoy it and this place we call home.

Tranquil Blue in the Garden

With the heat of summertime upon us I’m drawn to those areas in my garden that have blue, white and lavender flowers. A hot day just seems cooler there.

Washed out magenta is nature’s favorite go-to color and the shade that hybrids will revert to it if allowed to go to seed. Among gardeners, red is a favorite color. Orange and yellow come next, then pink and purple with blue and white both comparatively rare in nature last on the list.

geranium ‘Orion’

So naturally, most of us gardeners want the elusive blue flower in our gardens. Knowing that cool colors recede, place them around the edges or at the back of a garden to make your space appear wider or deeper.

True blue flowers are rare. We use words like cerulean, azure, cobalt, sapphire, turquoise, electric blue or steel blue when describing blue flowers. Hybridizers have tried for years to produce a true blue rose or blue daylily. Blue plant pigment is hard to manipulate. It occurs in the daylily as a sap-soluble pigment and is difficult to segregate. Lilacs, purples, orchids and mauves we have and working with them hybridizers may eventually get near blue, but pure blue probably never. Recently, some companies have found a way to insert some blue in the center of their daylily flowers but a totally blue daylily has never been produced.

Rose hybridizers striving for true blue have come close by

hydrangea macrophylla

crossbreeding lavender hybrid teas in order to produce offspring having optimum amount of cyanidin, the pigment that imparts purple or magenta tones and flavone, the pigment that gives light yellow tones.The results have been more of a silvery lilac or mauve. A blue rose is still in the future although labs in Australia and Japan are genetically modifying the pigments from petunias to produce a blue rose. Their results are not yet perfected and these roses are more of a lilac in color and can not survive conditions outside the lab. It is apparently very difficult to isolate the pigment cyanadin. Delphiniums have a monopoly on it.

omphaloides

The color blue is calming and tranquil. It is the color of serenity and peace and is said to slow down the metabolism and reduce the appetite. When brightened with white or combined with yellow or orange in a complementary color scheme the results of blue in the garden are breathtaking. The great English gardener Gertrude Jekyll used plants with golden leaves or clear yellow flowers to spice up blue gardens. Just remember that blues and purples are the first flowers to fade as darkness falls so be sure to have those whites and yellows to carry your garden into evening.

There are many blue perennials as handsome as they are durable that we can enjoy in our gardens today.
Some of my favorites are old fashioned hydrangeas, violas and campanula. Both are valuable in the shade garden along with omphaloides and brunnera. The blue spikes of a long blooming peach-leaf campanula just go together with the white and green variegated foliage of Jack Frost Siberian bugloss.

agapanthus africanus

In early spring we are dazzled by our native ceanothus which bloom with deep blue, sky blue or electric blue flowers. Emerald Blue phlox subulata carpets the ground in spring with clear blue flowers that top creeping stems. Penstemon Blue Springs, a California native hybrid, carries dense spikes of bright blue, bell-shaped blossoms.

Make sure your garden has a blue section to cool you on a hot day.

Why Prune in the Summertime?

Pruning is a good way to spend a couple of hours in your garden. I’m not talking about trimming plants into little balls but the kind of pruning that makes for a healthier and happier plant.

Sango kaku Japanese maple- summertime

If you grow Japanese maples now is the time to remove dead branches and train your tree to look like one of those specimens you see in the magazines. Thinning cuts build your ideal tree limb structure. If yours is a young tree, though, don’t be tempted to head back long branches too soon. As these mature they give your tree that desirable horizontal branching.

This principle is important to keep in mind when you train any young ornamental tree. Lateral buds grow along the sides of a shoot and give rise to sideways growth that makes a plant bushy.

Summer pruning of fruit trees controls size by removing energy-wasting water sprouts. Summer is also a good time to remove leafy upper branches that excessively shade fruit on the lower branches. Winter pruning is meant to stimulate the tree. Summer pruning uses thinning cuts-where the branch is cut off at its point of attachment instead of part way along the branch- and these cuts do not encourage new growth but control the size of your tree making fruit harvest easier.

Summer pruning also can control pests like coddling moths, mites or aphids. Just be sure to dispose of these trimmings and don’t compost them.

Espalier apple tree

If you have apricots and cherries, summer pruning only is now advised as they are susceptible to a branch killing disease if pruned during rainy weather. Prune stone fruits like peaches and nectarines after harvest by 50%. They grow quite rapidly. Apricots and plums need to have only 20% of their new growth pruned away.

Be sure to thin the fruit on your trees. That’s another good reason to keep them smaller so you can more easily reach the branches. The best time to do this is when the fruit is still small. Thinning fruit discourages early fruit drop and improves the quality of the remaining fruit. It helps to avoid limb damage from a heavy fruit load. Also it stimulates next year’s crop and helps to avoid biennial bearing. Left to their own devices, a fruit tree may bear heavily one year and then light or not at all the next year. Some types of fruit trees like peaches and Golden Delicious apples are likely to bear biennially if the current year’s fruit crop isn’t thinned.

While I have the pruners out I’ll be shearing back early flowering perennials to encourage another round of blooms. And I’ll add some more mulch to areas that are a little thin. I’ll be checking the ties on my trees to make sure they aren’t too tight and remove the stake if the trunk is strong enough to support the tree on its own.

Also I’ll be looking for any pest problems so I can do something about them before they get out of hand. I’m OK with a few holes here and there but a heavy infestation should be trimmed off or sprayed with an organic insecticide. I also inspect the tips of my fuchsias regularly for fuchsia mites and clip off any distorted growth. I hate to spray even organics on them due to the hummingbird activity.

Most importantly, enjoy your time outdoors. If a task is too big to do at one time, break it down into smaller sessions. As they say, take time to smell the roses.