Blazing hot weather one day, foggy the next – our summer is turning out to be a particularly hot one. The last two winters saw more than the usual freezing weather. If weather tells us what clothes to wear, then climate tells us what clothes to buy. Is all this proof of climate change?
Our planet has always experienced heating and cooling cycles. A warm period from 300-1300 AD allowed the Vikings to fish and farm Greenland. They were frozen out after 1300 when the Little Ice Age changed Greenland’s climate. A 20 year drought starting in 1276 probably drove out the cliff dwellers in Utah, Arizona and New Mexico and the Mayan culture collapsed about the same time as an extended drought occurred in Mexico and Central America.
People who cultivate plants have always taken climate change more seriously than most. Many tomatoes stop setting fruit when daytime temps stay above 90 degrees. Higher levels of carbon dioxide, a greenhouse gas, have been accelerating weed growth. Our best defense as gardeners is to choose wisely what we plant in the garden and how we water.
Start with smart design by evaluating how the space will be used and what plants will thrive with minimum of care and pruning. Select the best trees and place them to shade the south side of the house to reduce cooling costs.
Supplement the soil by making soil health a priority.
Examine your irrigation system and watering plan for efficiency and minimal waste.
Reduce, recycle and reuse whenever possible. Simple ways include reusing plant containers and composting organic waste and fall leaves.
We can all become stewards of the land by using these sustainable landscaping tips.
I love it when a nice reader takes the time to call me to suggest a topic they’d like to see me write about or remind them what needs to be done at a certain time of year. Take Helen, who lives in Spring Lakes in Scotts Valley, for instance. Helen told me she grows tomatoes in the summer and has 4 fruit trees including a satsuma plum, an espaliered apple and a tangerine. Helen battles peach leaf curl on her plum and coddling moth larvae inside her apples and would like to know exactly what to use and when to control these problems. So this column is for you, Helen.
I know we’ve had a lot of rain which makes gardening and spraying difficult. You can prevent or control many diseases and overwintering insects by applying a dormant spray this month. This can be the most effective spray of the season. Fungal diseases such as peach leaf curl, fire blight, scab and anthracnose as well as insects including aphids, San Jose scale, bud moth, leaf roller, whitefly larvae, mealybugs and mites can all be controlled.
There are several types of dormant sprays and all three types are considered organic. Lime-Sulfur or copper can be mixed with horticultural oil which smothers overwintering insects and eggs. This spray is good for all fruit trees except apricots which should be sprayed in the fall with copper and this month only with horticultural oil.
Apply dormant spray when the temperature is above 40 degrees. Make sure you cover every nook and cranny of each branch and trunk until the tree is dripping and spray the surrounding soil. Spray only plants that have suffered from pests or disease. Sprays, even organic, can kill beneficial insects as well. Even though they’re organic, dormant sprays can be irritating to skin and eyes, Wear long sleeves and gloves and eye protection.
Spinosad has been shown to suppress fungal diseases. Do this when the buds swell but before they open. Do not spray 36 hours before rain in predicted. Be sure to spray the ground around each tree.
Coddling moth control requires a different approach. The larvae of this particular moth is one of the few caterpillars that are likely to be found inside pear or apples. University of California Integrated Pest Management website has complete information about controlling this pest.
The bottom line for coddling moth control is the timing of insecticide spray applications, especially with newer, less toxic pesticides like spinosad. The coddling moth overwinters as full grown larvae within thick silken cocoons under loose scales of bark and in soil or debris around the base of the tree. The larvae emerge as adult moths mid-March to early April. To be effective your spray application must be timed for when when they are active.
Starting three to four weeks after bloom, check fruit at least twice a week looking for the first “stings” or any mounds of reddish-brown frass. If you scrape the frass away you will see the tiny entry hole where the newly hatched larvae has just entered the fruit. Spray the tree as soon as you see the first sting after removing any fruit with stings as the insecticide won’t kill any larvae that have already entered the fruit. Coddling moths can have three or four generations per year.
According to the website, for most backyard situations, the best course of action might be to combine a variety of non chemical methods and accept the presence of some wormy fruit. Be sure to cut out the damaged portions because they might contain toxins generated by mold.
Oh and by the way, Helen told me she is 88 years young so if Helen can do it, you can too.
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.
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.
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.
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 plants need water– even those that are tolerant of our summer dry conditions. Water makes up 90-98% of every plant we grow. It’s needed for photosynthesis, as well as reproduction and defense against pests.
What happens to a plant when the thermometer tops 100 degrees? Are there some plants that can survive tough times more easily?
Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. At temperatures about 104 degrees, however, the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous. Tomatoes, for example, will drop blossoms and not set fruit if temperatures are over 90 degrees. Plants that do endure hight heat may be stunted and weakened attracting pests and diseases even if water is available.
Plants have natural systems that respond to heat problems. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make “heat-shock” proteins which reduces problems from over heating. All these strategies can take resources away from a plants other needs like growth, flowering and fruiting.
It’s no surprise that many California natives are adapted to high temperatures. Some California native plants that can handle the heat with little water include salvia, mimulus, California fuchsia, eriogonum, manzanita, artemisia, California milkweed, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii, fremontodendron and holly-leafed cherry.
Other well adapted plants that are known to be more tolerant of heat include butterfly bush, germander, rosemary, smoke tree, rudbeckia, coreopsis, lantana, plumbago, gaillardia, lilac, sedums, oregano and verbena.
So how much water do different types of plants need during the heat of summer?
Be sure that you water trees and shrubs deeply checking soil moisture first with a trowel. Established small to medium shrubs should be watered when the top 3-6″ is dry, large shrubs and trees when the top 6-12″ is dry.
As a rule of thumb, trees and large shrubs need deep but infrequent irrigation. They should be on a separate valve than your smaller shrubs and perennials. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots grow 12-36” deep and require 10 gallons of water per inch of trunk diameter.
Apply water with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water district’s restrictions. Don’t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a smooth rod that’s 1/4 inch – 3/8 inch in diameter into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.
The roots of smaller shrubs are 12-24” deep in the soil. Established native shrubs may need only monthly waterings to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12” or so and may need watering once or twice a week depending on type.
With lots of mulch and the above watering tips you can keep all your plants happy and healthy
Spring might have officially started mid-March but judging from the wonky weather it’s hard to tell. We did experience a “Miracle March” with a pretty good dose of needed rainfall along with some very cold weather. You never know what to expect in March around here.
But now we’ve turned the corner on spring with flowers bursting open within hours on these nice days. The Black-headed grosbeaks have returned to my yard for the breeding season. Like clockwork they show up on almost the exact day each year. It’s my version of the swallows returning to San Juan Capistrano.
Looking forward to the rest of spring, here’s what I’ll be doing around here in April.
Hopefully we’ll have plenty of April showers. This latest rainfall is surely welcomed. One of the perks of a cool, rainy spring is that shrubs and perennials have longer to establish a good root system before hot weather arrives, ground covers have time to spread and shade the soil, conserving moisture come summer. What strategies can you follow that will make your garden low maintenance this summer and give you extra time to enjoy it?
Plant in masses. When designing or reworking your garden, make it
easy on yourself by planting fewer varieties but in greater numbers. Planting this way will reduce the number of different maintenance tasks for that area. For example, if you have a large hillside that you want to cover, plant it with a groundcover like ceanothus gloriosus which fans out 6-15 feet. Some manzanitas like arctotaphylos uva-ursi eventually spread to15 feet each. Sage leaf rockrose and germander are also good for sunny areas. A shady spot could be planted with ajuga, creeping mahonia or Walkabout Sunset lysimachia.
Another time saving strategy is to group plants with similar moisture needs. This may sound like a no brainer but if you have just one prima donna in a bed of more drought tolerant plants, you’ll be dragging the hose over to that bed for just one plant or having to run your irrigation system more for it. If you find that some of your plants are not quite as low water as you’d like, move those to their own spot. In general, plants with large leaves usually require more water and transpire faster while drought tolerant plants typically have one of more of the following characteristics: deep taproots and leaves that are smaller, silver, fuzzy or succulent.
Avoid putting thirsty plants in hard-to-reach places. If the irrigation system doesn’t reach that far, keep it simple by planting drought tolerant woody shrubs or perennials there.
Pluck weeds when the soil is moist and before they have gone to seed. Even if you don’t get the entire root of more persistent weeds, just keep pulling at the new growth. Eventually, the plant will give up having used up all of the food stored in its roots. I’m still battling hedge parsley with it’s sticky seed balls that will cling to my shoelaces and the dog’s fur if I don’t get it before it sets seed.
Plant edibles among your other plants near the kitchen. Tricolor sage looks great alongside other plants with pink and violet leaves. Purple basil planted below the silver foliage of an artichoke is another great combination. Lemon thyme growing next to a burgundy colored dwarf New Zealand flax would look spectacular, too. And don’t forget to plant decorative and delicious Bright Lights swiss chard with its stalks of yellow, orange, pink, purple, red, green and white throughout your beds. It’s one of the easiest vegetables to grow.
So get the lemonade ready to enjoy all your free time later this season.
If you read my column regularly or even once in a while you’ve probably heard me lament about the difficult growing conditions here in my garden. Between the sandy soil, 5 hours of intense sun but for only 6 months of the year, gophers, squirrels, moles, deer and chipmunks I’m happy if any plant thrives. So it is with pleasure that I report to you the small successes I’ve had lately and maybe give you hope that you might also grow plants that provide some color and fragrance in your garden along with attracting hummingbirds, songbirds, bees and butterflies.
As the sun shifts lower in the sky, my garden becomes shadier each day. The soil is still warm, however, and that encourages root growth so even though I won’t see much happening above ground until late next spring hope springs eternal and I am driven to plant more natives as well as other appropriate plants that will fill in those blank spots.
This week a clump of deep pink gaura lindheimeri is blooming like crazy. If I had my druthers I wouldn’t have planted it among a stand of orange flowering California fuchsia but it still looks great against the gray foliage of the epilobium or zauschneria or whatever it’s called now days.
Gaura ’Siskiyou Pink attracts butterflies and hummingbirds and needs only occasional water. The books will tell you gaura requires full sun but mine is thriving without a lot of sun. Don’t be afraid to try a plant you like despite what the books tell you.
Same goes for the light requirements of the California fuchsia. Mine is happily spreading and it gets only partial sun for part of the year. Las Pilitas nursery website, a great source of information, does say they will tolerate part-shade and commonly grow where there is extra moisture in the winter and spring, gradually drying through fall. Guess that 140 inches of rainfall I got up here in Bonny Doon last winter would fall into that category. As far as the renaming of plants California fuchsia apparently is now called epilobium canum but the name zauschneria may come back so call them whatever works for you.
One of these days I want to plant a few more native plants that will tolerate shade and attract wildlife. Toyon with it’s red berries is high on my list as is Pacific wax myrtle. I have a pink flowering currant which is doing well as well as sambucus mexicana which the hummingbirds, jays and chipmunks like and a Black Lace elderberry.
Of course, all the different ceanothus do well in partial shade, grow fast and the birds and bees love them both in bloom and now that they are full of berries and seeds. My covey of quail find the berries irresistible. Apparently porcupine like them also but fortunately for my dog, Sherman, I don’t have any of those.
California native Pacific Coast Iris, Woodland Strawberry, Heuchera maxima, Western Columbine, Bleeding Heart, Mimulus and Wild Ginger all do well in my lean, shady, sandy soil. For some reason I don’t have any any coffeberry or any Oregon Grape but they are both on my wish list. Coffeeberry is one of the best all around native plants for wildlife and mahonia or Oregon Grape bloom in the winter and provide much needed nectar for hummingbirds.
Take advantage of the fall planting season to spruce up the problem spots in your shady garden. Email me at firstname.lastname@example.org if you would like more suggestions.