Monthly Archives: October 2015

aphids, IPM, organic gardening, pests

Troubles in the Garden

Milkweed_aphids
Milkweed aphids

Some of us enjoy sitting in our gardens, relaxing and watching birds and other wildlife. Others grow fruit and vegetables and know their way around the kitchen. Whatever you like to do sometimes pests get in the way.

In my own garden recently I discovered my butterflyweed covered with yellow milkweed aphids. They?re not interested in any other plants just this one. Oleanders get this same sucking pest also. I?ve washed them off twice with a strong spray of water but must have missed a few as they are back. Unfortunately, I haven?t seen any monarch butterflies to help me with this problem. I?d rather not even use an organic pesticide to control the outbreak. It would harm any monarch eggs that I?ve overlooked.

With pest control on my mind this week, I received an email from fellow Press Banner columnist, Dr. Terry Hollenbeck. ?I thought of you when I found an article in an old gardening magazine?, he wrote. ?It?s ?The Home Gardener? and was published in September, 1945.?

DDT ad_The-Home_Garden-Sept1945
DDT ad in ‘The Home Garden’ magazine published September 1945

Dr. Hollenbeck scanned the pages from his own magazine and sent them to me. Terry goes on to note that the editorial about the new wonder insecticide DDT warns readers in 1945 to proceed cautiously with it. Then later in the magazine on page 99 in a half page ad there appears an advertisement for DDT, the ?Army?s sensational insect killer that gardeners have been waiting for?that is absolutely safe to spray?.

There has been a lot of research now on DDT and it?s effects on our bodies and that of wildlife. I was surprised when I Googled DDT that it?s still being used in the world and also found a published study debunking it?s adverse effects on raptors. Guess one can find statistics to support any argument if you look hard enough.

Here is what I found out about current use of DDT that I found interesting.

Back in 1972 the EPA (Environmental Protection Agency) issued a cancellation order for DDT use in the United States based on research showing adverse environmental effects to wildlife and potential human health risks. Studies have continued to show a relationship between DDT exposure and reproductive effects in humans and as a result, today, DDT is classified as a probable human carcinogen by U.S. and International authorities.

India is the only country now producing DDT. China and North Korea having discontinued production in recent years. 12 countries still use DDT for vector control of mosquitos and protozoa – the parasitic diseases of malaria, dengue and black fever which kill more than 800,000 people each year.

Many organizations are now promoting an integrated approach to mosquito and protozoa carried diseases. It?s not a DDT or nothing solution. Some of these organisms are developing a resistance to DDT and other chemicals. Like in our own backyards, you have to look at the whole picture. Successful programs to educate communities about non-chemical methods of control mosquitos are underway in many countries such as Vietnam.

DDT is known to be very persistent in the environment. It accumulates in fatty tissues and can travel long distances in the upper atmosphere. Because of its persistence, there is still concern for residues in the U.S.
Today nearly 40 years after DDT was banned in the U.S. we continue to live with its long lasting effects. According to the organization Pesticide Action Network, USDA found DDT breakdown products in 60% of heavy cream samples, 42% of kale greens and 28% of carrots. These breakdown products of DDT were found in the blood of 99% of people tested by the CDC.

Something to think about when I see all those mustard yellow aphids on my asclepsias. Maybe I?ll get the hose out one more time or rub them off with a gloved hand.

compact shrubs, Deer Resistant Plants, drought tolerant gardens, drought tolerant plants

Changing Times – Changing Gardens

Maybe our gardens in California should never have looked like a Monet painting filled with layer upon layer of water thirsty perennials and lush green lawns big enough for a soccer match. Because we were first settled by Easterners who could grow these plants with natural rainfall I?m going to give us a pass. It wasn?t our fault. But now we are wiser and smarter. We may have been kicking and screaming at first but all us us now accept that water is limited and we need to use it wisely.

That doesn?t mean, however, that we have to live in graveled yards with no landscaping. Our goal should be to figure out what the new California landscape should realistically look like and plant accordingly. We can still be surrounded by green and silver foliage and colorful flowers that look lush without breaking our water budget.
Look outside the old box and discover a whole new plant palette and a way of gardening that works for all of us.

drought tolerant plant plugs
Drought tolerant plant plugs

Recently in the mail, I received a collection of low water use, low maintenance plants native to Australia. I plan to trial the small plugs in my own garden but I know already that they are going to be winners. I have seen a couple of them at the wholesale nurseries. Others are improved selections of known tough, drought tolerant plants. They are well suited to our Mediterranean climate, easy to grow in well drained soils and hardy in winter. I?m looking forward to a time when they are available in local nurseries. In the meantime, I plan to specify them where appropriate in future landscape designs.

I?m excited about all 5 varieties of plants I received. Three are grass-like and the other two are compact versions of well known shrubs.

You might be familiar with the compact bottlebrush ?Little John?. Breeders now have come up with a new improved version called Callistemon ?Better John? because of its vigorous growth and dense blue-gray foliage. This 3 foot tall by 3 feet wide shrub is easy to grow, quick to establish and is long lived in the landscape. Hummingbirds love the 4-6 inch long red flowers during the spring.

The other shrub variety I am going to test is Westringia ?Grey Box?.? Westringia are deer resistant and very drought tolerant once established and ?Wynabbie Gem? and ?Morning Light? have been popular for years for this reason. Grey Box is a new dwarf form with beautiful grayish-green foliage. It doesn?t need pruning to keep it at 3 feet tall and wide. From late winter to summer, white quarter-sized flowers appear in small clusters along the stems. I?m anxious to grow this shrub myself.

lomandra
Lomandra ‘Breeze’

A couple of the grass-like plant plugs I received are an favorite of mine. I?ve seen lomandra ?Breeze? growing in heavy shade and also in sun. Deer don?t like it and it looks great with little water. Now there?s a new cultivar called ?Baby Breeze’ which stays at a graceful 18 inches tall. If you want the look of a short grass with no maintenance Lomandra is the new go-to plant. It even has yellow-orange tiny flower spikes in late spring.

Lomandra ?Katrinus Deluxe? is the other selection I?m going to grow out. It?s extremely drought tolerant, very shade tolerant, cold and heat tolerant and deer resistant also. It looks like an ornamental grass but you don?t have to cut it back in winter. It?s evergreen even when temperatures drop into the teens.

Dianella ?Little Rev’ is the last plant I?m looking forward to growing. This flax lily has an weeping architectural habit. It?s a very tough and drought tolerant grass-like plant good for erosion control as well as planting on it?s own or in groups. In spring it blooms with masses of small dark violet flowers. This is a clumping plant for full sun to partial shade that slowly spreads by rhizomes. As with the others this plant also is low maintenance and requires little water once established.

I?ll keep you posted as I discover new plants for our changing times and changing gardens.

California Native Plants, fall foliage

Fall Color in the Garden

fall color_maples-Yellowstone_Lake
Fall color at Yellowstone Lake

I?m starting to see a little fall color showing in some trees and shrubs. Might not be much but I?m always optimistic about such events. When I was in Wyoming the aspen and maples were beginning to turn red and gold and shrubs with berries acted like bird magnets. During this fall planting season look again at where a low water use plant that colors or fruits in the fall might be a great addition to your garden.

What causes those fabulous fall colors? The colors are always there. They are just masked by the green chlorophyll in the leaves busy making food by photosynthesis while the sun shines.

Come autumn, shorter days and cooler temperatures cause the trees to switch into energy-storage mode, at which point their leaves stop producing chlorophyll. For the few weeks before the leave fall to the ground, they are colored only by their natural pigments. It’s these colors – red and purple anthocyanins, yellow and orange carotenoids – that make fall foliage so glorious, sometimes anyway.

fall color_mixed forest_Wyoming
Mixed forest fall color near Grand Tetons, Wyoming

Weather conditions also play a major part in fall color. Some years the show is more dramatic than others. The best conditions for intense leaf color to develop are dry sunny days followed by cool -but not freezing – nights.

A warm, wet autumn will almost surely result in less-than-spectacular foliage because the process of chlorophyll loss will be less consistent. Freezing temperature meanwhile can cause leaves to drop suddenly denying the opportunity to enter a slow, colorful dormancy.

This year because many trees are stressed by drought they may not put on their usual show before the leaves drop. I have some native big leaf maples that are probably not going to turn color before leaf drop. Stress can be caused by pests, disease, injury or drought.

California native Western redbud turns yellow or red in the fall if conditions allow. This plant is truly a four-season plant starting in spring with magenta flowers, then leafing out with apple green heart shaped leaves. Colorful seed pods give way to fall color. This small native tree or large shrub does well as a patio tree in gardens with good drainage.

Other native plants like Spicebush and Western azalea turn yellow or gold in the fall. A native vine that lights up with the onset of autumn is Rogers Red California grape. If you have an arbor, wall or fence that needs covering quickly this is your plant. The green and gray leaves are transformed in autumn into great draperies of rich, scarlet red leaves with clusters of summer fruit turning all shades of purple.

Other low water use trees and shrubs that provide fall color include Chinese flame tree, Idaho locust, Chinese Tallow, Chinese pistache, Crape Myrtle and Smoke tree.

A great tree for the gardener interested in edibles is the Fuyu persimmon. This beautiful small tree is ornamental with glossy green leaves and also offers a dramatic fall display in shades of yellow, orange and red. Bright orange fruit begins to develop in late October and clings to bare branches usually through December. The tree looks more like it’s covered with holiday ornaments than fruit. And have you priced persimmons in the store lately?

Blueberries are a must for the edible gardener. They make a beautiful hedge and provide showy red or yellow fall color. Because of our colder winters here in the mountains, we can grow both northern highbush which are self-fertile and southern highbush which produce better with another type to pollinize them. They can be great foundation plants around the home as well as in the garden. Blueberries are low maintenance. Just a light pruning once a year after the season?s harvest and the shrubs will maintain a tidy appearance. Most are pest and disease resistant and since they don?t have thorns, they are child and pet-friendly.

Now through late fall is a good time to shop for trees that change colors because you can see in person just what shade of crimson, orange, scarlet or gold they will be.