The weather this spring has been a challenge for gardeners.  Temperatures in the 80s in March and April fooled some people into planting too early and the frosty temperatures over the last two weeks found them regretting their early enthusiasm.

      There is nothing we can do about the overeager fruit trees, strawberries and grape vines that leafed out or flowered too early and had their tender growth killed by frost.  The hope is that enough of the flower buds survived for at least a reduced crop, and that there is enough life in the grape vines to send out new leaves.

      Some vegetables and flowers are tough enough to take a light frost.  If you’ve already got pansies, violas or snapdragons outside, they probably did fine in the cold weather over the past couple weeks.  Likewise, potatoes, peas, kohlrabi, radishes, beets, carrots, cabbage, spinach and other greens almost certainly survived unharmed.

      There are other plants that are much more sensitive to cold temperatures.  Before planting you should be very certain that either the last frost has occurred or that you have a plan to protect tender plants if a late frost is forecast. 

      Tomatoes, peppers, beans, cucumbers, eggplant, melons, squash, pumpkins, and basil will be killed or severely set back by even a light frost.  Some bedding flowers can take temps hovering around 32° but others like impatiens and begonias will become a slimy mess when the temperature drops.  Other tender bedding plants include ageratum, celosia, dahlia, geranium, lisianthus, nicotiana, moss rose, salvia, cleome, vinca and zinna.

      What if your tender plants are in the ground and a frost is forecast?  Cover them.  Plastic tarps, old shower curtains, window curtains, blankets or sheets can be laid gently over rows or beds of plants.  Stake the covers down or put rocks or other heavy items around the edges so they don’t blow off.  If the young plants will be crushed by the weight of the cover, use wooden stakes to tent the cover a few inches above the plants, making sure the edges of the cover reach the ground.  Bushel baskets or buckets can be upended over individual plants like tomatoes and peppers.

      The worst damage from frost actually happens in plants when they warm back up the next morning.  Frost freezes the water inside the plant’s cells, which damages the cell walls.  When the warmth of the morning sun hits the plants, they defrost rapidly and the cell walls rupture.

      There is a way you can try to save the plants by preventing the rapid defrosting.  Lightly misting or spraying the foliage with water before the sun reaches it will help the plant to thaw without the shock of sudden warmth.  

      Even hardy plants that are lightly touched by frost may take awhile to recover.  Make sure they are watered regularly, but know that frozen or damaged roots don’t take up water as easily, so it’s easy to overwater and drown a recovering plant.

Little red buds are appearing in the rhubarb patch.  It will be another month or more until it is ready for harvest, but now is the time to divide it if you haven’t done so for several years.  Dividing rhubarb keeps it producing well.  If the stalks are getting spindly, it’s time to divide.

      Use a spade to dig all around the crown and then lift it from the soil.  Break the crown into pieces, making sure each piece has one or two buds and a root.  If you cannot identify a bud, just divide it into several good-sized clumps.  Replant the divisions so that the buds are just covered with soil, about the same depth it was before you dug it up. 

      While the rhubarb is out of the ground, take the opportunity to remove weeds and add some rotted manure or other organic fertilizer to the soil. 

      Do not harvest any rhubarb the first year after dividing.  The plants need this year to re-establish themselves.  Harvest lightly the second year, and after the third year, harvest as much as you want, never taking more than half the stalks at a time.  Fertilize after harvest is completed each year.

      To avoid the waiting period, use a sharp spade to slice down the middle of the crown while it is still in the ground and lift just half of the plant.  Continue to harvest from the original plant while the new divisions are establishing themselves.

      All that said, if your rhubarb hasn’t been divided for many years and is prolifically producing good thick stalks, don’t bother dividing it until you have to!

      Rhubarb will grow in just about any kind of soil, but does best in loose, well-drained, fertile soil. 

      To harvest rhubarb, select firm, crisp stalks and gently tug and twist them from the ground.  Cut off the leaf.  Rhubarb leaves contain oxalic acid and are toxic, so wash your hands after harvesting.

      Store fresh rhubarb stalks, unwashed, in the refrigerator up to two weeks.  Rhubarb can be rinsed, cut into inch-long pieces, and frozen in freezer bags.

      Always remove the thick flower stalks that shoot up from the center of the plant as soon as you see them.  They take energy from the plant that is put to better use in growing the stalks you will harvest.  Some rhubarb cultivars are more likely to produce flower stalks than others, and some produce them some years and not others, depending on soil conditions and weather.

      If you are planting rhubarb for the first time, there are several cultivars to choose from.   If you are buying crowns to plant rather than getting divisions from a friend, read the descriptions to help you decide which one to choose.  Some cultivars are sweeter than others, and colors range from green to pink to red.

Have you ever bought a packet of special seeds, maybe something a little unusual or more expensive than you’d normally buy, only to plant them and find that not one seed germinated?

      Some seeds, especially those of  prairie plants, woody perennials and trees and shrubs, need help in breaking dormancy before they germinate.  This characteristic, called “innate dormancy” helps insure their survival in nature.  The seeds know to wait out the winter or a dry season before sprouting.  And if their pre-germination requirements aren’t met, they just won’t germinate.

      For some seeds, this means exposure to cold, also called stratification.  This is most easily accomplished in the refrigerator.  Mix the seeds with an equal volume of moist, clean sand, vermiculite or sawdust and place them in a sealed plastic bag.  The mixing medium should be barely wet as too much moisture will cause the seed to rot.  Most seeds need three to four weeks of refrigeration, but some need much longer.  A reputable seed company will have this information on the seed packet.  If you’ve collected the seeds yourself, some internet or library research will be necessary to determine stratification time.  Count backward on the calendar and start the cooling period so that it ends when you are ready to plant.

      Another option is to plant the seeds in fall and let winter do the stratification for you.  This may work, but realize that your valuable seeds may be subject to extreme temperature fluctuations, excessive wet or dry conditions, and damage by birds, rodents or other animals.  Also, note that some seeds, lilacs and arborvitae for example, are double dormant and require a period of cold stratification followed by a period of warm, moist stratification, so if planted outdoors, they may take a year or more to germinate. 

      Other seeds, like morning glory, sweet pea, okra and others have very hard seed coats that inhibit water absorption.  They need something to help soften or break the seed coat before they can germinate.  This is called scarification.  In nature, freezing temperatures or soil microbes soften the seed coat in winter.  Scarification can also occur as seeds pass through the digestive tracts of animals.

      There are several methods home gardeners can use to scarify seed coats.  Large seeds can be nicked with a sharp knife or cut with a razor blade.  Be careful not to damage the embryo inside the seed.  Medium and small seeds can be rubbed between two sheets of sandpaper.  To scarify large numbers of seeds quickly, slip a sheet of coarse grit sandpaper inside a jar, add the seeds, screw on the lid and shake the jar until the seed coat wears down.  The seed coats will look dull when they are sufficiently scarified.

      Even seeds with thin seed coats can be helped along.  Soaking large seeds like peas, beans or nasturtiums in lukewarm water for several hours before planting will speed germination.

      One frigid winter night I stepped out the door carrying a beautifully blooming kalanchoe houseplant loosely protected with plastic, a housewarming gift for my neighbor.  Ninety seconds later when I arrived at my new neighbor’s door, the kalanchoe was dead.

      The lesson here is that most houseplants originate in tropical regions and cannot tolerate even a short blast of cold.  If you are giving or receiving a poinsettia, Christmas cactus or other houseplant this time of year, special care must be taken when transporting them outdoors. 

      The key to keeping the plants alive is to protect them with as many layers of paper, plastic and even blankets as possible.  It might not be a pretty presentation, but at least it will be alive.  It would be smart to warm the car up and move it as close to the door as possible when a tender plant is to be carried.

      If you are the recipient of a gift plant, check the potting soil to be sure it is moist and water immediately if it is not.  Slip the pot out of the pretty foil that surrounds it and let it drain before replacing the foil.   You can keep the foil around the pot for a few days, but then it should be removed and the pot inside should be placed on a saucer for drainage.

      Inspect the plant, including the undersides of the leaves and the stem to be sure no greenhouse pests have been relocated to your home.  Look carefully, especially at poinsettias, to see if tiny little whiteflies are flying around the plant.  Most pests can be removed with just water using your kitchen sprayer or the bathroom shower.

      If the pot feels unusually light, the plant is root bound and it should be transplanted to a larger pot with a good potting mix.

      In general, houseplants and gift plants should be kept in a warm location near a south or west facing window.  Poinsettias do best in indirect sunlight, but Norfolk Island pines and Christmas cactuses can be placed right in the sunshine. 

      Make sure the plants are not near a furnace register, fireplace or other heat generating appliance and move them away from the window if it gets cold in the area at night.  The key is to prevent rapid temperature fluctuations.

      The soil of poinsettias, Christmas cactuses and Norfolk Island pines should be kept constantly moist, but not dripping.  Do not allow the plants to sit in standing water or you risk root rot.

      Last winter the rabbits did a lot of damage to landscape plants.  The only sure way to protect your landscape from hungry bunnies this winter is by fencing.  Simple chicken wire fencing is easy to use and relatively cheap.  Use a wire cutters to cut the length you need, place it around the plant and hook the cut wires into the openings on the other side and you’re done.   

      Last winter the snow got so deep that many people were forced to put another level of fencing above the first layer. 

      Plants like arborvitae, magnolia, burning bush, spirea, bridal wreath, ornamental plum, and Nanking cherry are especially susceptible to rabbits, but if they get hungry enough, they will sample anything.  So if you have a plant that is valuable to you, it is best to fence it. 

      There are rabbit repellant sprays you can purchase, but neither the products nor the sprayers work as well in winter as in warmer weather, and really, do you want to be out there in the cold after every snowstorm re-spraying your plants?

      Another important winter preparation is laying a 4-6 inch layer of winter mulch.  Not all plants need this, but any perennial, tree or shrub facing its first winter should be mulched.  This isn’t to protect them from cold temperatures, but rather from repeated freezing and thawing that will damage the roots or even heave the plants above the soil line.  Mums, coral bells and many roses are especially susceptible to freeze/thaw damage and should be mulched every year. 

      But wait – don’t put the winter mulch down yet!  Do it after the ground has frozen, typically around Thanksgiving.  Otherwise you will make a nice little mulch nest for mice and other critters, complete with a snack bar.  For the same reason, keep the mulch a short distance away from the plant stems.

      An exception is strawberries, which should be entirely covered with mulch when temperatures are forecast to dip to 20º F.

      Good materials for winter mulch are loose materials like pine needles and hay or straw.  Wood chips and bark also work.  Leaves are not good as they tend to clump together into a heavy mat from the weight of snow.

      Remember to turn off the water supply to outside faucets, drain and put away hoses, and make notes of any ideas you have for next year’s garden.

Take the time now to prepare your yard and garden for winter.  When spring comes you’ll be glad you did.

      Cut the grass short to discourage voles and mice from making nests below the snow.  Rake leaves out of areas where they pile up and shred them with the lawn mower for free lawn fertilizer.  They will decompose to feed the soil and will be gone by spring.

      An exception to this is the leaves of fruit trees or grapes.  They should be raked and removed from the area so that leaf diseases aren’t encouraged to stay around for next year.

      If there isn’t sufficient rain, water evergreen plants deeply before the ground freezes.  Evergreens continue to transpire water from their needles all winter and this last chance for a good drink is it until the ground thaws in spring.

      After the ground is frozen, place a winter mulch such as pine needles, pine boughs, shredded leaves, straw or other light material around all young perennials.  Also mulch around any tree, shrub or perennial where the winter sun shines directly on the root zone.  The point of the mulch is to prevent the soil from repeated freezing and thawing which damages the roots.  Do not put mulch down before the ground freezes because that’s like putting a welcome sign out for mice to come and build their winter homes.  They’ll enjoy snacking on the stems or bark of your plants as well.

      There are sprays you can buy to repel rabbits from your plants, but if you truly value a certain plant, fencing is the only sure thing.  Chicken wire is relatively inexpensive and is easy to cut and place around trunks or stems of vulnerable plants.  In spring it can be removed and rolled up to be used again in future years.

      The trunks of young trees, especially fruit trees, should be wrapped so the low winter sun doesn’t scald the bark.  Inexpensive brown paper tape is available at garden centers for this purpose.

      Wait until January or February to prune fruit trees or vines.  Pruning is a growth-promoting process and a week of warm weather in December could jump start growth that will be killed by cold weather to follow.

      After the ground freezes, pile fresh top soil 8-10 inches high around rose bush stems.  For even more protection, surround the mounded soil with chicken wire and stuff the inside with leaves, hay or straw.  If you decide to protect your roses with styrofoam rose cones, puncture several 1-inch holes around the top so that air can circulate inside.  You must remember to remove the cones on warm spring days or the roses will cook inside them.  Be ready to put them back on, however, if a cold snap is in the forecast.

Garden supply stores have row upon row of handy tools for the gardener and mail order companies have whole catalogs of gardening tools.  But if you need a tool to do something right now and don’t have the time or inclination to run to the store to buy it or to the internet to order it, you improvise.  Many of the items I use to in the garden were never meant to be used the way I utilize them. 

      One of the handiest items is a five gallon bucket of the type that sealant for asphalt driveways comes in.  It is useful for mixing soil, carrying sand, hauling tools, and toting weeds to the compost.  A rectangular plastic kitchen dishpan works for many of the same tasks and is also useful for carrying produce from garden to kitchen.

      Instead of filling the bottoms of container plantings with heavy stones or gravel for good drainage, use styrofoam packing peanuts.  For very large containers, fill the bottom with empty pop cans, then packing peanuts, then potting mix.  This makes containers much lighter and easier to move and saves money on potting mix.  Place a coffee filter in the bottom of the pot before planting so the soil doesn’t wash out the hole. 

      Yogurt cups are perfect for starting pepper seedlings; my tomatoes get their starts in cut off half-gallon orange juice cartons.  Plastic gallon milk cartons have many uses in the garden.  Cut the bottoms off and cut a slice out of the top of the handle.  Poke a stake through the handle and into the ground next to tender seedlings in spring.  When frost threatens or on windy days, flip the container around the stake and over the plant to protect it. 

      Plastic milk cartons are also useful to hang in apple trees to prevent damage from coddling moths.  Cut a hole a few inches square somewhere in the top half of the carton.  Mix 1/2 cup vinegar, 1/2 cup water and a few tablespoons of molasses in the carton and hang it by its handle in the apple tree right after blossom drop.  The solution will attract moths away from the apples.  Check periodically and refill when the solution evaporates.

      A third use for plastic milk cartons is for watering.  Punch holes in the bottom and bury the carton up to its neck next to tomato plants.  Fill the container with water and it will trickle out the bottom to reach the plants right where they need it – at their roots.

      Thick layers of newspaper can be used as mulch to kill grass for a new garden bed or between rows in a current garden to suppress weeds.  Wet it down and cover it with a heavier mulch to keep it from blowing away.

      I have knives intended for use in the garden, but what I reach for when I need to trim away roots to repot or divide a plant is a sharp kitchen knife.  It works better and is always handy.

      And for what do I use the great knee pads my mom got me for Christmas to wear for weeding?  Kneeling to scrub the kitchen floor!

      Do you routinely fertilize your lawn or garden?  How do you know you are giving your plants the right kind or amount of fertilizer?  You can save money, improve the health of your plants and protect the environment from fertilizer run-off by doing a soil test that will tell you exactly what your landscape needs.

      The test results will only be as good as the sample you take.  The best results will be from a test that is a mix of soil from at least five different spots.  But don’t combine soil from your lawn, your vegetable garden and your flower beds into one sample.  The plants that grow in each of these areas have very different requirements and the soil is likely very different in each of these spots because of how you’ve treated the soil in the past.  Make a composite sample of five spots from your vegetable garden and separate composite samples from your flower beds and lawn.  You might even take separate samples from your front yard and back yard if the quality of the turf is very different.

      To take a sample, dig down and take soil from about 4 inches in an established lawn and 5-7 inches in a garden or new lawn.  You can use a shovel, trowel or soil auger to get the soil.  From the five separate spots collect a total of one to two cups of soil. 

      The Winnebago County Extension office has wax-lined soil sample bags (or you can use a clean, strong plastic bag) and Soil Information Sheets that you fill out and return with your soil sample.  You need to fill out one sheet for each sample.  The more information you provide, the better the recommendation you will receive.  Return the soil sample to the Extension office or send it directly to the UW Soil and Plant Analysis Laboratory, 5711 Mineral Point Road, Madison, WI  53705.  The phone number is 608-262-4364.  You can also print the Soil Information Sheet from the internet at http://uwlab.soils.wisc.edu.

      Each soil sample tested costs $15.  The test will tell you your soil pH, lime requirements, organic matter percentages, phosphorus needs and potassium needs.  There are additional fees for any special soil tests.  Some of the special tests are for lead, zinc, boron, calcium and magnesium.  Excesses or deficits of any of these in the soil can cause problems with plants.  The fees for those tests can also be found at the website mentioned above.

      Soil samples can be taken any time the ground isn’t frozen, but early spring and late fall are best.  Take the sample when the soil is relatively dry and don’t sample right after applying fertilizer as that will be an inaccurate representation.  Experts recommend that soil samples be taken every three years.

The recent rains have been like a mega-dose of multi-vitamins for flower and vegetable gardens.  Unfortunately, the weeds have taken the vitamins also and are proliferating.  The good news is that weeds pull easily from rain-soaked soil.  Spend the time in June to keep ahead of the weeds and you can relax in July and August, but wait for the plants to dry off before weeding or you may inadvertently spread diseases among your good plants.

      Just like flowers, weeds can be annuals, perennial or biennials.  Annual weeds generally have a fibrous root system which spreads just beneath the soil surface, unlike the fleshy tap roots of the perennial types.  No matter the type of weed, it is important to remove them before they go to seed.  Most annual weeds can be easily pulled or sliced off just below the soil surface with a hoe.  Do not chop at the soil with your hoe or you will bring more weed seeds to the surface that will germinate. 

      Perennial weeds spread by means of underground stems and root parts and also by seed.  Hoeing or tilling them only makes the problem worse because new weeds can sprout from each chopped up piece of root.  They are best pulled with the aid of a dandelion digger or asparagus fork to ease the roots out of the soil.  Weeds that have not yet gone to seed can be composted or just left to dry out on top of the soil.

      One of the most-asked questions is how to eliminate the lawn weed creeping charlie, also known as ground ivy.  Dissolve ½ cup 20 Mule Team Borax, found in the laundry detergent aisle, in one gallon of warm water.  This translates to 1¼ cups borax for the average 2½ gallon sprinkling can, which is enough for 1,000 square feet of lawn.  You can also use a sprayer which gives a finer, more even coverage.  Don’t use a sprayer that you have used previously to apply any type of herbicide or you may kill your grass along with the creeping charlie.  Before you start, measure out 1,000 square feet so you have an idea of the area you should cover.  Applying the solution too thickly will result in burnt grass.  Check the weather forecast and apply the borax solution when there is no rain predicted for at least 48 hours. 

      You may have noticed something that looks like foam or soap on many plants and weeds this month.  That is from the aptly-named spittle bug, but the foam is actually the bug’s excrement.  The bug, which looks like a little light yellow seed, is hiding inside the spittle and sucking the juices from the plants.  They are easily controlled by washing the foam and insect off with water from the hose.  I used to be diligent about this, going out daily and spraying spittle bugs from all my plants, but I got tired of doing so last year and just left them alone.  I noticed very little damage to the plants and was relieved to give up the task and devote my time to weeding instead.

      March gardening reminders:  If you haven’t already done so, it is time to prune apple and pear trees, grape vines, deciduous trees except for maples, evergreens and woody shrubs except for early bloomers like forsythias and lilacs.

      If you plan to start flower or vegetable seeds indoors for outdoor planting in May, check the seed packet as to how far ahead to start the seeds and use a calendar to count the weeks backward to figure out when seeds should be started.

      During the second half of March, spread corn gluten meal on your lawn as a non-toxic method of controlling dandelions and other broadleaf weeds.  Corn gluten meal inhibits germination.  To be effective, it must be spread before the weeds germinate.  So if you see little dandelions in your lawn . . . too late!  Corn gluten meal can be purchased at Greenville Co-op on Hwy. 76 in Greenville.  Call 757-6556 for hours and price.  Uncover roses and other shrubs that were covered or wrapped in Styrofoam or plastic.  The warm spring sun can cook those plants inside their non-permeable covers.  Rake winter mulch aside but be ready to cover plants again if nighttime temperatures are forecast to be below the mid-twenties.