What Should You Do For Your Plants AFTER a Freeze?

Sometimes a gardener feels as if they're in a heavyweight boxing match: Your Tender Plants vs. Mr. Freeze. Your citrus, succulents and perennials that may thrive in milder climates might be able to take a frosty punch or two here in the Sacramento/San Joaquin Valleys, foothills, and inland portions of the Bay Area. But several cold blows to the flowers, leaves, stems and roots? 

We aren't talking about light frosts, or temperatures that hover around 30 degrees (F) for a couple of hours; that would be normal; the possibility of a frost in Sacramento is anytime between November and late March. The most typical frost period here is December and January. Usually by late February, gardeners thoughts - mistakenly - have turned to planting warm season annuals and putting away the frost cloths for the season. What area gardeners are going through right now is several days of extended hours of below freezing overnight temperatures, with prolonged bouts of plant-killing cold in the mid-to-low 20's. 

So, what should a shivering gardener do...after a hard freeze, when temperatures are at or below 28 degrees for several consecutive hours? Should they:

a) remove all plants that look frost-bitten; 

b) prune away all freeze-damaged plant parts;

                   

c) Purchase and plant again this month those same varieties of trees, shrubs, perennials and annuals;

                 

d) Water the garden, even if the plants resemble toast;

            

e) Fight the urge to prune and plant by staying indoors, next to the wood stove.

The answers happen to be the easiest to accomplish on a cold weekend: d) and e).

If plants in your garden look blackened and wilted now, new growth may emanate from the base of the plant when the weather warms up in a couple of months.

New growth beneath the frosted branches of a geranium.

Pruning away the dead portions now exposes buds that may still be alive; another frosty morning could wipe out those survivors. Keep the shears in the garage and let the dead portions of the plants protect the understory.

 

 It may take until mid-Spring before you see new growth. Patience is key before you pick up the pruners. In the meantime, tolerate the ugly.

Make sure your garden and potted plants remain moist, especially if it isn't raining. Water gives off heat, and this can protect plants from freezing, especially borderline citrus trees, such as lemons and limes. Damp soil retains heat better than dry soil, protecting roots and warming the air near the soil.

Succulents, such as cactus, are the exception, however. According to the Arizona-based Desert Botanical Garden, most succulents survive freezing temperatures best if the soil around them is dry. 

It's dead, Jim.

Some of those dead plants may be summer annuals that survived our unusually mild early and mid-winter. This impatiens,  for example took its sweet time to croak. Mornings hovering around 25 degrees can do that to a summer annual. Put them in the compost pile; plant more in the spring, after all danger of frost.

Frosty the Ficus

What about those plants that have frozen past the point of no return? Should you replace them with the same varieties? That frozen ficus may be Mother Nature's way of telling you: "Hey! This ain't San Diego! Pick outdoor plants that can take colder temperatures!"




Oh, and keep your frost protection gear handy...just in case.

Garden Resolutions: Then and Now

Back in 1991, I started what became an annual event: writing a "Garden Resolutions" article each January for my weekly newspaper column. In the 20 years since, it's eye-opening to see what has changed...and what is still the same for backyard gardeners.

First a look back at that first "Garden Resolutions" column, 20 years ago:

• Use less water.  Turn off your lawn's automatic sprinklers during the winter. Install drip irrigation or micro spayers around outdoor trees and shrubs. Don't let sprinkler water puddle up and run off the grass. Keep a bucket in the shower to catch the cold water in the morning before the hot water reaches you; then, use that bucket of water for your indoor and outdoor potted plants.

•  Consider alternatives before spraying potentially dangerous chemicals. To get rid of aphids, a blast of water to the backs of leaves may work as well as applying malathion or diazinon.  Insecticidal soap can control a host of bad bugs (such as aphids, whiteflies and spider mites) without harming the good ones (ladybugs, praying mantids and honey bees). A pie plate of stale beer can do in snails. 

But, if you decide to use chemical sprays:
• Use a separate sprayer, either hose-end or tank sprayer, for different tasks. Use one sprayer for herbicides (such as Roundup or any weedkillers); use another sprayer for insecticides and fungicides. It's not uncommon for gardeners to lose prized plants because they didn't rinse out a herbicide thoroughly from a sprayer before using the same unit for insect or leaf disease control. Rince out the sprayer and nozzle three times after each use.

• Read all chemical label instructions carefully. Don't apply more of a chemical than what is called for on the label. Not only is it wasteful, but it's more dangerous for the person applying it as well as the environment. 

• Enjoy gardening in 1991. Don't let the work involved sour the experience. Remember what awaits you this year for your efforts: the beauty of the first tulip or marigold, the taste of that first homegrown tomato and the bounty of a seemingly endless supply of summertime zucchini.

• And don't plant so much zucchini this year.

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In 2011, the emphasis is still on water conservation. 
But the disappearance of many dangerous, non-selective garden chemicals (especially diazinon) has opened the door for other chemicals that may or may not be just as harmful. Clouding that issue even further: the marketing for those products as "natural" or "safe" can mislead backyard gardeners into using something that is neither safe or natural (organic). Add to that all the misinformation that is now available on the Internet, and it's no wonder gardeners are confused. 

(note to kids: yes, there was an Internet in 1991, but it was limited to services that were primarily text services that were e-mail and bulletin-board based, such as Prodigy, CompuServe and Delphi. Ask your parents about CompuServe. It was the cat's meow!)


Here's the 2011 list of "Garden Resolutions":

• The key to plant success? The right plant in the right place. Get a soil test done. Read up on plant requirements before purchasing them.

• Reduce the size of your lawn.

• Plant more edible ornamentals.

 

• Put in plants that attract pollinators (insects and hummingbirds) and beneficial insects (and birds).

 

 


 • Check soil moisture before watering.

• Use drip irrigation, microsprayers or soaker hoses instead of overhead sprinklers, where it is applicable.







• Searching for reliable garden information online? Don't forget  to add ".edu" into the search box at Google, Yahoo or Bing to bring up university research first.

• Be wary of advice on the gardening forums on the Internet. All gardening is local. What worked for a gardener back East may not work for you. 

• Just because it is on the Internet doesn't make it The Truth. Check their information sources.

• Trying to control garden pests? Start with the least toxic alternative. Consider mechanical, physical and cultural controls before choosing chemicals.


 
• When choosing garden chemicals, don't believe the advertising. Believe and follow the fine print on the chemical label.








• After you have used it, use it again. Make your own compost from kitchen scraps and leaves. Make your mulch from shredded and chipped tree limbs from your own property.

 


• Mulch, mulch, mulch. 

• And don't plant so much zucchini this year.
(some things never change.) 


Add your 2011 Garden Resolutions!

Growing Great Gladiolus

For the gardener with little time to spend in the yard, gladiolus are a colorful, easy care plant, perfect for borders and large containers. They make great cut flowers, too! Selecting a variety of glads and staggering their planting dates will produce a succession of height and bloom from spring through fall.


GLADS ARE EASY TO GROW 
Most garden soils that will produce a good crop of vegetables or weeds will also grow good glads with little or no added fertilizer. Glads prefer good air circulation and full sunlight but will do reasonably well with a little high shade in early morning or late afternoon. Choose an area with good drainage. Glads don't like wet feet! Raised beds are an ideal solution.

 

Plant only clean, plump gladiolus corms (also known as bulbs). Here in the valley, foothills, and Bay Area, plant a few glad corms every week or two, from late January through early April. That way, there will always be a gladiolus in bloom throughout the warm weather months.

Plant gladiolus corms three to five inches deep and from four to six inches apart, with the tip side facing upwards.


GLADS ARE EASY TO CARE FOR...AND ENJOY

 Water regularly while they are growing or blooming, perhaps once a week. Water twice a week during heat waves. 
Weed by shallow cultivation and hand weeding. A three inch layer of mulch of bark, straw, leaves, grass clippings, etc., between rows will discourage weeds and help conserve moisture.

To get the most enjoyment of glads as a cut flower indoors, cut off the flowering stalk when the lowest buds begin to open. Be sure to keep at least four leaves on the plant to allow the corm to renew itself for the following year.
At the end of the season, cut off the stem just below the lowest flower buds. This keeps the energy from the leaves flowing towards the corm, not to seed production.


GLADIOLUS CAN GET BUGGED  
Thrips are one of the most damaging insects to glads, especially in the summer. Look for silvery flecks on the foliage and silver or brown blemishes on the flowers and buds. You may also see their black droppings on the leaves.
These tiny (less than 1/20th of an inch long) creatures scrape away the plant tissue, suck the juice and lay their eggs inside. Control thrips with a blast of water from the hose or insecticidal soap. Healthy plants can outgrow thrip damage.


CAN YOU DIG IT? YES, BUT NOT EVERY YEAR
 Here in most areas of California, where the ground doesn't freeze in the winter, you may choose not to dig up your corms. However, disease brought on by too much rain and too cool of a soil, as well as eventual crowding, may reduce the amount and quality of next year's bloom.

It is suggested that you dig and divide your corms every couple of years in the fall, being sure to discard any damaged or diseased corms.

The plant should be separated from the corm as close to the corm as possible, either by hand breaking or cutting with pruning shears.
 
Store any lifted corms in a cool, dry place, in single layers in a flat or ventilated tray. Then, replant those corms the following February or March.

A Great Year for Tomato Blossom End Rot

2010 is shaping up as a great year for backyard tomatoes...with blossom end rot. During tomato planting time here (late April-early May), the weather was cooler than normal, and much wetter. That pattern continued through the rest of May; our typical valley heat didn't arrive until late June. Tomatoes took their time. There are still gardeners waiting patiently for their beefsteaks and other main season tomatoes to turn red (true here, too).

For those tomatoes that are ripening, many gardeners are now contending with a major outbreak of blossom end rot. Tomato plants with blossom end rot show small, light brown spots at the blossom end of immature fruit. The affected area gradually expands into a sunken, leathery, brown or black lesion as the fruit ripens. Hard, brown areas may develop inside the fruit, either with or without external symptoms.
 
According to the tomato heads at UC Davis, the problem occurs when tomato plants have grown rapidly during the early part of the season and are then subjected to hot dry weather when the fruits are in an early stage of development. You know, sort of like the weather in late June.



Some tomato varieties are more susceptible to blossom end rot, including plum and pear-shaped tomatoes.

Although the weather and the variety of tomato sets the table for blossom end rot, many other factors are major contributors. 

Mainly, you. 

Yes, blossom end rot is related to a deficiency of calcium in the tomato fruit, but that occurs for several reasons that can be classified as “operator error”. Among them:

• Too much water.
• Not enough water.
• Irregular soil moisture, brought on by, um, irregular watering.
• Too much nitrogen fertilizer.
• Planting in soil whose pH is not conducive to calcium uptake by the plant (below 5.5 or above 8).
• Planting in poorly drained soil.
• Planting in too sandy of a soil.
• Improper planting (spreading out the roots when planting helps the plant adapt better)
• Excessive levels of potassium.
• Excessive pruning.
• Lack of an organic mulch. (organic mulch helps moderate soil temperature and moisture fluctuations)
• Using a plastic mulch which might raise the soil temperature too high.
• Planting certain tomato varieties that are prone to blossom end rot, especially narrow paste tomatoes.

The most critical mistake gardeners contribute to blossom end rot: not monitoring the soil moisture at root level.  
Although the surface of the soil may appear dry, the moisture level a few inches down may be correct. If more water is added at that time, then the soil becomes so moist that oxygen is unavailable for root growth and calcium will not be absorbed. Why? Excess soil moisture, combined with a lack of soil oxygen, speeds the formation of Casparian strips, deposits on the young root tips that have become suberized, waxy substances through which water and nutrients cannot move.

If the soil in the root zone is too dry, then the calcium will not move to the roots. Dry soil and hot, dry, windy days create a water and calcium deficiency in the plant. Even a brief soil water deficit can disrupt water and nutrient flow in the plant. If this occurs while fruits are developing, blossom-end rot will likely develop.

Automatic irrigation timers may save you time, but it may not save your tomato plants from blossom end rot. Watering schedules need to be adjusted to the weather to maintain even soil moisture.

And when it comes to garden problems, many folks think the answer is, “buy something and put it on the plant”.  

Buying stuff won’t necessarily end blossom end rot.
 
Among the “store-bought remedies” that are frequently suggested that have been proven to be of little or no value to ending blossom end rot:

• Applying a foliar calcium spray to the tomato leaves. In University tests, studies showed that calcium does not move from leaves to the fruits. Thus, foliar sprays of calcium won't correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) through which calcium can be absorbed. Contrary to past belief, the direct application of calcium as a spray is ineffective.

• Adding a calcium supplement, such as gypsum, limestone, or eggshells. Perhaps. But it depends on your soil. 

• Limestone can raise the pH in soil to a range more favorable to tomatoes and calcium uptake, around 7.0. But if your soil is already in that range, adding limestone may raise the pH to the point where calcium uptake is again, slowed.

• Adding crushed eggshells to the soil well before transplanting time may help overcome any calcium deficiency already in the soil. But it ain’t gonna help your tomatoes if they are already in the ground.

• And gypsum (calcium sulfate)? Dr. Linda Chalker Scott of Washington State University's Horticulture Department, and author of the award winning book, “The Informed Gardener”, says home gardeners are wasting their money. “Most urban soils are not improved by adding gypsum,” she states in her on-line newsletter, “Horticultural Myths”. “Adding gypsum to sandy or non-salty soils is a waste of money, natural resources, and can have negative impacts on on plant, soil and ecosystem health.” However, she points out, gypsum can improve the structure and fertility of heavy clay soils; but consider another undesirable result to adding gypsum: Gypsum can have negative effects on mycorrhizal inoculation of roots.

Maintaining the proper balance of potassium, phosphorus and other soil nutrients and avoiding excessive growth due to over-fertilization with nitrogen is recommended. Some university studies, including a study from Cornell University, suggest that a low nitrogen, high phosphorus, low potassium fertilizer (such as a 4-12-4) may help control blossom end rot.

Excess levels of ammonium (NH4-N), magnesium, potassium and sodium have been reported to reduce the availability of calcium, according to the journal "Agronomy". That same study reported that the use of nitrate nitrogen (NO3) might stimulate Calcium uptake.

Their best advice: A soil test should be conducted to help determine what needs to be added and what should not be added to your garden soil.
 

And, use a moisture meter. 

 

How Much Water Does Your Lawn Need?

                      

HOW MUCH WATER DOES YOUR LAWN NEED???


During the Central Valley's hottest months (June through September), you may need to add an inch and a half to two inches of water to your lawn each week, divided into two or three applications. 
      The California Irrigation Management Information System can let you know what the current evapotranspiration rate is in your area of the state. This is a great way to pinpoint the exact amount of how much water is leaving your soil and lawn on a weekly basis, so you can adjust your sprinkler timing. This is a free service, but you have to register.


DO NOT WATER YOUR LAWN EVERY DAY! This practice can lead to serious lawn problems, such as shallow lawn roots (making the lawn more susceptible to drought and insect damage), fungal growths and diseases.


To determine how much water your sprinklers are putting out:


• Position 6 to 10 flat-bottomed, same sized containers around your lawn. Use drinking glasses, Tupperware, tuna fish or cat food cans; containers with taller sides will keep the water from splashing out. Put some in the greenest areas; put some in the areas that are struggling.


• Turn on your sprinklers for 30 minutes. Then, measure the amount of water in each container. There should not be more than a quarter-inch difference among all the containers. If there is, readjust or add to your sprinklers to hit those areas that aren't getting as much water. If, on average, you are getting a half-inch of water per container during that 30 minute test, then you need to water your lawn for two hours a week in the summer, to put two inches of water on your lawn. In this example, you would water your lawn twice a week, for an hour each time.


• You may need to adjust this timing if you see water streaming off the lawn. In that case, reduce the amount of time the sprinklers are on at any one time. Then, add a second cycle three or four hours later.


• It is best to water with rising temperatures, which in the summer, is from about 4 a.m. to 10 a.m. Earlier is better.