Carol Allen may be a plant geek, horticulturist and organic gardener, but she’s also a self-professed LAZY gardener.  So when she teaches her favorite ways of dealing with garden pests, you know it’ll be the most effective, easiest to do, and also the easiest on the environment. Here are the highlights of her talk at our Beltsville store today on this favorite subject of hers.

The Best Defense? Healthy Plants

easiest ways, which also happen to be the easiest on the environment.  Here are the highlights of her talk at our Beltsville store today on this favorite subject of hers.

The Best Defense?  Healthy Plants

• So put the plants in the right place, which starts by giving them the amount of light they need.   Since most of us overestimate the sun we get, it helps to check several times a day and note the actual number of hours.
• Test the soil, at least for pH. The test is cheap and easy and ensures that your plants get the nutrients they need.
• Add plenty of organic matter.  Carol’s favorite is her own homegrown compost, followed by locally made Leafgro compost.  She keeps some bags on hand at all times.
• Water correctly. That means no broadcast spraying – plants need a long drink, not a quick shower. The water has to get not only to the rootball, but also saturate it. Correct watering is deeply and thoroughly, not frequently and shallowly.
• Mulch for plant and soil health.  For veg gardens she loves straw mulches but for trees, shrubs and flower beds she uses shredded bank or her own cropped-up dead leaves.  Why waste ‘em?
• Don’t over-fertilize! Research at the University of Maryland and elsewhere is showing that less is more – it prevents fertilizer from running off into the Bay and killing our crabs.  (Speaking of which, crabshell-based fertilizer is excellent!)  Carol uses little to no fertilizer in her garden but when she does feed, she uses Espoma’s line of organic products.  They feed slowly and safely.

Best Methods for Dealing with Pests

• Prevention – using that list above.
• Knowledge – identify the pest before deciding on a “treatment,” if any.  Two great sources to help with that are Va Tech and the University of Maryland.
• Barriers, like floating row covers
• Mechanical removal
• Encouraging beneficial insects
• Chemical controls, especially spot-spraying with safe organic products (yes, organics are chemicals, too.)
• And take notes so that next year you have a chance to prevent the problems you’re dealing with this year.
  

  Ladybug Larva

Recognizing some of Gardeners’ Best Friends

Sure, we all know that ladybugs (more properly called ladybug beetles) eat destructive insects like aphids, but do you recognize this little guy?  It’s the ladybug beetle’s larvae and they’re “bug-eating machines”!

For the green lacewing (below), it’s the same story.  Those babies don’t look like much but they’re great workers in the garden.

Green lacewing adult and larvae

Below, more beneficial insects – the soldier beetle and an assassin bug eating a pest.  But be careful of the assassins – if handled roughly, they’ll bite the gardener, too.

Soldier beetle (L) and Assassin bug (R)

More good-guy bugs include spiders, yellow jackets, parasitic wasps (which plant their eggs IN aphids!), syrphid flies, and wheel bugs.

How to Attract Beneficial Insects?

Grow a diversity of plants.  Especially among vegetables, it’s important to grow a variety of these flowers that do a great job of fighting pests on your edibles:  carrot, yarrow, Queen Anne’s lace, zinnia, ageratum, sweet alyssum, blanket flower, cosmos, sunflower, tansy, marigold, aster, daisies, mums, black-eyed susan, coneflower, coreopsis, bee balm, salvias, nasturtiums, and poppies.  Plus, these herbs: mints, dill, fennel, coriander, parsley, anise, thyme, sage, oregano.  This is generally the same group of plants that attract butterflies.

Organic Pesticides

• Horticultural oil like All Season Horticultural Spray Oil works by suffocating the target bugs, but make sure you get the spray on their bodies. Hort Oil is effective in controlling cucumber and bean beetles as well as on ornamentals for scale insects. Be sure to follow the temperature requirements on the label, to avoid burning the plant’s leaves.
• Neem oil like Schulz’s Fungicide (that’s the product name, but really a multipurpose spray) is another good one for general use.
• Horticultural soaps are products Carol doesn’t use as often because they kill only larvae and are less effective on adults, while oils kill both. Also, they sometimes burn leaves.
• Bt (Bacillus thuringiensis) is a naturally occurring bacteria that messes with the digestive system of caterpillars, causing them to die of starvation. Asked how to use this product without killing the caterpillars we WANT (butterflies especially) Carol explained that Bt should be used selectively on just the plants that are being fed on by the target insects (like for cabbage worms). So for example, you wouldn’t spray it on parsley or pawpaw trees because they’re fed on by butterfly larvae.
• Spinosad, contained in Captain Jack’s Dead Bug Brew, works on beetles, caterpillars, sawfly larvae, and soft-bodied insects. It’s another naturally occurring bacteria. Carol recommends it for such ornamentals as roses and Mugo pine.

Next, Carol highlighted some of the worst pest offenders, and what to do about them.

Tent caterpillar's egg mass, and caterpillar-filled tent.

Eastern Tent Caterpillar

This native caterpillar feeds on cherry, apple trees, and serviceberries and can be vanquished easily if you spot the black egg case in winter. Just rub it off of the twig or branch it until it drops to the ground. If you miss it, you can’t miss the caterpillar-filled tent that appears in the crotch of target trees in the spring – remove that with your gloved hand and send it off with the trash.

From left, gypsy moth egg mass, aphids, and cabbage worm

Gypsy Moth

These voracious eaters are doing great damage to our trees, especially oaks.  If you spot their egg mass in the spring, just scrape it off with a putty knife, bag the mass and throw it away.

Aphids

Aphids come with a leg-up in the survival sweepstakes of Nature – they’re born pregnant!  The best way to deal with them is to simply wash them off, and attract those great aphid-eating beneficial insects.

Cabbage Worms

If you grow vegetables in the cabbage family, you’ve probably battled these little crop-eaters.  They’re best prevented with the use of row covers, or by spraying with Bt.  Sure, they can also be removed by hand but it’s hard to stay ahead of their munching.

Japanese beetles and brown marmorated stink bug.

Japanese Beetles

Introduced to the U.S. in the early 20th century, Japanese beetles are kinda fun to hand-pick and drop in soap water but can be largely prevented by spraying milky spore on your lawn. – because lawns are where the grubs live for most of the year. Just don’t buy traps for them – they only attract MORE beetles to your garden.

Brown Marmorated Stink Bug

This is a newcomer to our gardens, having been discovered just 14 years ago, but it’s rapidly becoming a major pest here in the Mid-Atlantic region – even in our homes! So lots of research is being done on this stink bug, especially by the University of Maryland, including on the efficacy of traps. In the meantime, there’s one product Carol recommends – the clay-based Surround. Spray Surround on developing fruit such as tomatoes, peaches, and apples to protect them. It’s also a good idea to clean up the vegetable garden before winter, to reduce the chances of wintering-over pests – not just this stink bug but many others that could emerge in the spring to eat your crops.

Lacewing larvae photo credit.  Lacewing adult photo credit.  Ladybug beetle larvae photo credit.  Soldier beetle photo credit.   Assassin bug photo credit.  Tent caterpillar photo credit.  Gypsy moth photo credit.  Aphid photo credit.  Cabbage worm photo credit.  Japanese beetle photo credit.  Stink bug photo credit.

Posted by  Susan Harris.

Click here for all the February tips from the experts at Behnkes and the University of Maryland.    Veg-growers, note that it’s time to start broccoli, cabbage, Chinese cabbage, parsley, onion and leeks indoors.   And have you done your winter pruning yet?

Ask and ye shall be answered!

Resident horticulturist Carol Allen encourages blog readers to ask questions – about veg-growing or anything else – and she’ll provide answers here for everyone to read.  Just put them in a comment – in the top-right corner of this blog story – and we’ll get you the answer pronto.

Photo credits:  Broccoli seedling,  cabbage.

Larry Hurley’s Favorite February Tips 

• Remember that it’s best to stay off of soggy, wet soil. Walking on it or “working” it with hand tools or tillers will compress it. Clay soils, which drain poorly to start with, will be made even worse by trying to work with them when they are wet.
• Buy Valentine’s Flowers and plants for your loved ones, and even your liked ones. Nothing compares to the color and fragrance of real flowers.
• Take some trips to the great greenhouses: United States Botanical Garden is always worth the trip downtown, and the Conservatories at Longwood Gardens are beautiful any time of the year.

Miri Talabac’s Favorite February Tip

Remember to water your outdoor container gardens once in a while when the weather’s mild and the pots have thawed. Dry winter air, mild temperatures and sunny days can still cause dormant plants to loose water, which can be more damaging than injury from cold alone.

Edibles

• Time to start these seeds indoors: broccoli, cabbage, Chinese cabbage, parsley (which can be started as early as January), onions and leeks.  Click here for lots more about seed-starting and veg-garden prep in February by resident horticulturist Carol Allen.
• Scout for Eastern Tent caterpillar egg cases on your apple, sherry and crabapple trees – just twist them off.
• If you have a cold frame, you can sow an early crop of spinach and lettuce in it this month.
• Buy your veg seeds now before the supplies dwindle.
• If you’ve had problems with aphids, mites and scale insects, spray trees thoroughly with a dormant oil spray before bud break, making sure that temperatures are expected to remain above 40 degrees F. for the 24 hour period after spraying. Follow label directions.

Lawn

• Late February through the end of March is the second best time (the optimum time is late August through mid October) to over-seed your lawn to make it thicker or to cover bare areas. The freezing and thawing of the soil this time of the year helps the seed to get good soil contact.
• Avoid excessive walking on your grass when it is frozen to avoid damaging the crowns of your grass plants.

Bulbs

• Don’t worry about your bulbs popping up early; it won’t harm them – unless we get a hard freeze just as they’re about to open.  If that happens it’ll weaken the stems and make them floppy.  A plastic garbage can or waste basket over the clump for the night would help to keep off the frost, and hold a bit of ground heat in.
• If you put protective evergreen boughs over your early spring bulbs, remove them now to enjoy their early bloom.
• As your bulbs pop up and you can tell what they are, that’s a good time to mark them (with labels or drawings).  That way, you’ll know where they are after they’ve gone dormant this summer – if you want to dig them up, plant around them, etc.  (When to move your bulbs?  When the foliage has yellowed and the plant is going dormant.  Though if they’re tulips, it may not or may not be worth the effort.  Most bloom for just a year or two, so it’s best to plant new ones each year.)

Annuals

At the end of February, look at the long-range weather forecast. It may be time to put out pansies or cool-season vegetable plants if it’s going to be mild for the next ten days.

 Trees and Shrubs

• Winter is the best time to prune deciduous (leaf-dropping) trees and shrubs because you can easily see where branches rub against each other, spot dead or broken branches, and see how you might prune to improve form. Remove suckers and water sprouts, too.  But remember that you will be removing flower buds on spring bloomers, so be conservative if that is an issue.  Here’s more about pruning from the U. Md.  You may notice excessive sap bleeding from pruning cuts on elm, maple, birch, dogwood, beech, walnut, magnolia, tulip poplar and redbud. This bleeding is harmless to the tree.
• What NOT to prune now? Anything that flowers in the spring (if you care about seeing those blooms).
• If you have yews or camellias, look for white cottony masses on the undersides of needles/leaves. These are scale insects and they should be sprayed with horticultural oil later in the season when the youngsters (aptly named crawlers) emerge.
• Got deer?  Now’s the season when they home in on our more expensive plants, like trees and shrubs.  So apply Liquid Fence or Plantskydd (our favorites) monthly.
• If/when it snows, try to prevent snow and ice from building up on gutters and eaves above shrubs. Gently sweep snow loads off of shrubs to prevent breakage.
• Remove and destroy bagworm bags from affected trees- principally on evergreens. The bags contain hundreds of eggs that will hatch out and feed next spring.
• This is a good time to inspect winter creeper and Japanese euonymus foliage for scale problems.  Prune out damaged leaves and control the scale insects by spraying the healthy leaves with dormant oil.  Be sure that temperatures are expected to remain above freezing for a 24 hour period after spraying.
• Hemlocks infested with the woolly adelgid can be sprayed with dormant oil any time in February – as long as the temperatures are expected to remain above 40 degrees for the 24 hour period after spraying.

Houseplants

• Keep an eye out for pests on your houseplants – like spider mites, mealybugs and scale insects.  If you act quickly, most pests can be eradicated with simple methods, like a spray of water, spraying with insecticidal soap, or swabbing the critters (especially mealybugs) with a Q-tip dipped in rubbing alcohol.
• Be careful not to overwater.  And remember – don’t fertilize houseplants this time of year.  It will tell you when it’s ready for action.

Wildlife

• Keep bird feeders clean and replenished throughout the winter months.  If you started feeding them in early winter, they’re depending on you.
• Likewise, remember that wildlife needs a water source through the winter. Refill your weather-resistant birdbaths regularly.
• If you have a pond, keep a portion of the surface clear of ice at all times. If the water freezes over completely your fish may die. When ice forms, there is a strong chance that gasses from organic debris at the bottom of the pond will build up in the trapped water and harm the fish. There are a number of electric pond de-icers available that will provide a constant unfrozen area in the water. There are also some small bird bath warmers that do the same thing.
• Ceramic and plastic birdbaths are especially vulnerable to cracking in cold weather and should be stored indoors.  Metal ones should be unaffected by freezing so keep them outside.
• If you garden near deer, keep up the deer repellants through this, the most vulnerable time for evergreens.  Use monthly, rotating two or more different products.
• This is the mating season for foxes. Late at night they make a noise that sounds like a person screaming.

Studying and Planning, if not done last month

Maintenance Jobs for Winter, especially clean-up, if not done last month

Photo credits:  Cardinal by Natalie Brewer.  Broccoli seedling,  onions, cabbage, lawn.

Carol Allen in teaching mode.

We had another great turn-out, this time for Carol Allen’s talk about getting the vegetable garden ready, and I can see why she’s developing such a loyal following.  Not only is she an “honest-to-God horticulturist,” in her words, but a terrific speaker and teacher – and those are few and far between.

First she reminded us why it’s so great to grow our own food (freshness, control over inputs, cheaper than Whole Foods, soul-deep satisfaction, etc.) and said this is the perfect time to plan and start this year’s veg garden.

She handed out this chart from the University of Maryland, which lists first dates for planting outside for each vegetable.  Then counting back the number of weeks it takes to germinate, February is the time to to start broccoli, leeks, onions, parsley, and cabbage seeds indoors.   Consult the seed packets for each plant you grow for the number of weeks ahead of time to start the seeds indoors.

Seed-Starting Indoors

Start with a top-notch seed-starting medium, not just any potting soil.  The ones for seed-starting are more finely milled.  Carol’s favorite?  “I’m a Pro-Mix babe.”  Okay!  And always, always use fresh soil – if the soil has been used before, it’s too compacted, and has lost its porosity.  (If you have left-over potting soil in a bag, that’s fine because it hasn’t been compacted by watering).

Seeds can be started in any number of containers – 4″ pots if they’re large seeds that grow quickly, like beans.  Free containers like plastic carry-out containers work great, as do Solo cups and the seed-starting flats available at your friendly garden center.

But wait – if you’re re-using pots, it’s really important that they be clean, and putting them in the dishwasher is not good enough.  First, to remove that salty crust, scrub them with white vinegar.  Then to remove disease organisms, soak them overnight (at least 4 hours) in a solution of 10 percent Clorox.  Do this for both plastic and terra cotta pots.

Fill your container with the medium, and sterilize the soil with boiling water to kill surface spores that can (and often do) cause damping off – that horrible collapsing of the whole plant.  Let the soil cool down, and you’re ready to plant.  But resist the urge to pat down the medium!!

If you’re using those little 3×3 inch cells, put two seeds in each cell, then sacrifice the weaker one after they’ve germinated.

Okay, now you’re ready to plant, spacing the seeds according to the seed packet (great info there – read it all!).  Insert labels – tongue depressors work well but there are other types available.  In addition to labeling the actual seeds, Carol keeps track of the date planted and the date it germinates.  The record of your own successes and failures is more valuable than any book.

Now where to place your seeds?  Not necessarily in light – read the packet.  Some seeds, like pansies, germinate better in the dark.  If they do need light, a window is okay IF it receives full sun.  A better technique is to use lights – a fixture that is 48? long equipped with four, 40-watt bulbs.  Start with the light about 4″ above the soil but make sure the system allows you to move the light upward as the seedlings grow.

If using lights and when the light fixtures are very close to the seed bed, Carol recommends using a small personal fan to blow over the seeds 24 hours a day. That will insure good air circulation – to avoid that horrible damping off mentioned above.

As to whether or not a plastic cover should be used, there are pluses and minuses.  Unless it’s propped up, the air underneath the cover can get too hot.  But with the cover down, it’ll keep out mice if they’re a threat.

Thinking ahead to April

If you can, prepare the soil in your garden ahead of time. Sometimes the soil is too soggy early in the spring when you want to plant (Carol preps some of her beds in the fall for early planting.)  Just make sure the soil has dried sufficiently before working it.

After the plant-outdoors date (here’s the link again), you’ll need to harden the seedlings off over the course of a week.  That means putting them outside in the shade on a balmy day, then gradually giving them more sun until they’re ready for their full-sun spot in the ground.

When you remove the seedling from its container to plant it out, spread the bottom of the root ball to give its roots maximum exposure to the soil.  And now’s the time to install cutworm collars and floating row covers, if needed.

Q&A Time

• After Carol called corn a “space hog” a questioner asked – even planted in the traditional Three Sisters?  Yep, those three sisters need to be widely space so you can get to your harvest.
• What to do if you don’t have full sun?  With a half day of sun you can grow greens in succession.
• And speaking of full sun, how is that defined?  “Horizon to horizon.”  If you have less than that you can still grow sun-loving crops but the yields will be lower and they’re be more vulnerable to disease.  So use your best sun wherever you have it – in containers on the roof or in a driveway.  “Hubby’s BMW goes on the street!”
• Is it okay to use the rest of the seeds in a packet at a later time? Yes if you fold and tape it, seal in a clean mason jar and store it in a dark, cool place.  Brassicas and tomato seeds last for years.  Just make sure they’re safe from mold, heat, and moisture.  Here’s how to tell if your old seeds are still viable:  Place 10 seeds between moistened paper towels, roll up the towel and place it in a plastic bag. Put the bag on top of the refrigerator or other warm location and check after 5-7 days to see what percentage has germinated. Discard seed lots with less than 75% germination.
• How about those upside-down tomato towers?  They’re a “cute novelty” but a waste of money, producing disappointing results.  No “pluses and minuses” on that one!
• In preparing your beds, add compost or Leafgro – Carol does every time she turns her soil.
• Is it okay to use fireplace ashes in the garden? Nope.

Disease Q&A

• A participant with cucumbers that don’t produce confessed that they’re growing in the same place every year.   “Bad, bad child!  Rotate your crops!!”  Seems that powdery mildew has been a common problem with cucumbers in the last couple of years, and rotating crops is an important way to avoid many diseases.
• More ways to prevent powdery mildew?  Buy mildew-resistant plants, give them full sun and good air circulation, or spray for it.  Organic gardeners can use horticultural oil or a mix of baking soda in water but the spraying must be done before problems occur (think of it like applying sunscreen).  The preventive spraying needs to start by May 1 and be repeated every week to 10 days, and it’s worth doing if you’ve had problems with that plant in the past.
• To prevent tomato blight, rotate crops and mulch well because the disease spreads through rain splash.  The spores have been known to ricochet as high as 6′ up from the ground.  Carol’s favorite mulch is straw, 3-4 inches of it.

Ask More Questions Here

Carol is available for any and all questions about growing vegetables!  Just ask them in a comment to this post, and we’ll add her answers pronto (and notify you by email, too).

Posted by Susan Harris.

This Saturday, October 15 from 9 to 4:30 in Potomac, everyone’s favorite orchid expert will be answering your questions, diagnosing your orchid problems, and repotting every orchid in sight (okay, just the ones that need it but she’s ready).

Carol has become so popular with local orchid growers, we’re noticing some regular attendees, and new converts to the joys of orchid-growing.  So we’ll be offering Carol’s help this Saturday and again on November 12 and December 10.  She’s that popular.

More about  Carol

A quick look at her resume reveals knowledge of waaaay more than orchids.   Looks like we could pick her brains on just about anything plant-related:

Carol Allen has been involved in gardening and horticulture since childhood.  She has worked in almost all aspects of the horticultural industry and confesses to being a confirmed ‘plant-a-holic’. Carol enjoys teaching people about plants and their care and occasionally teaches at the University of Maryland, College Park.  Fascinated by the interplay of pest and prey, Carol recently returned to college and earned a degree in horticulture.  She is currently enrolled as a graduate student in plant science at the University of Maryland where her research is in transfer of virus disease in orchids.

Carol speaks to various plant groups and societies on a wide range of horticultural topics.  She can be heard at Brookside Gardens teaching organic gardening, speaking on building a butterfly garden at a local garden club, teaching master gardeners about houseplant care, or talking about pests and diseases at a regional orchid society.  She is an integrated pest management specialist and a licensed pesticide applicator in the states of Maryland and Virginia.  Readers are informed and entertained by her column in the Washington Gardener magazine on pest issues.  Carol confesses to growing a wide range of plants in and around her home that she shares with cats, anoles, tropical frogs, tropical fish, and pet snakes.