Damping-Off Plant Disease

What is damping-off?  Damping-off is a common and fatal disease that affects all types of plant seedlings.  The disease is most prevalent when seeds are germinated in cool, wet soils.  Fortunately, seedlings are susceptible to damping-off for only a short period following emergence.  As plants age, their susceptibility to damping-off declines.

Lower stem collapse of Zinnia seedlings due to damping-off.
Lower stem collapse of Zinnia seedlings due to damping-off.

What does damping-off look like?  Seedlings killed by damping-off initially are healthy but shortly after emergence become infected at or just below the soil line.  The lower stems of the seedlings collapse, and the seedlings fall over onto the soil surface.  The seedlings subsequently die.

Where does damping-off come from?  Damping-off is caused by several soil-borne water molds and fungi, including (but not limited to) Pythium spp., Rhizoctonia solani and Fusarium spp.  These organisms readily survive and are moved in soil or on soil-contaminated items such as pots, tools and workbenches.

How do I save seedlings with damping-off?  Seedlings with damping-off will die and cannot be saved.  Proper prevention is the only way to avoid problems with this disease.

How do I avoid problems with damping-off in the future?  When planting seeds, make sure that work areas, tools and pots are pathogen-free.  Decontaminate tools and workbenches by treating them for at least 30 seconds with 10% bleach or (preferably due to its less corrosive properties) 70% alcohol (e.g., rubbing alcohol or certain spray disinfectants).  Decontaminate pots by washing them with soapy water to remove bits of old soil, soaking them for at least 20 minutes in 10% bleach, and then rinsing them thoroughly to remove bleach residues.  DO NOT reuse plastic pots if you have had problems with damping-off or root rots in the past, as they are difficult to decontaminate.

When planting, use a well-drained, pasteurized potting mixture.  DO NOT use garden soils as they often contain damping-off pathogens.  DO NOT plant seeds too deeply, and germinate seeds at high temperatures, so that seedlings rapidly grow out of the stage where they are susceptible to damping-off.  DO NOT overwater as damping-off organisms are more active in wet soils.  If the techniques described above do not work, then consider using fungicide-treated seed.  In particular, plants grown from captan-treated seeds tend to have fewer problems with damping-off.

Article by Brian Hudelson UW-Madison

Source: Damping-Off | Plant Disease Diagnostics Clinic (wisc.edu)

Pelleted seed gives gardeners a sown in advantage

Have you noticed the windowed packets of seeds at garden centers with brightly colored “seeds”? These pelleted seeds are small or irregular seed that have a specialized inert coating applied to improve planting, spacing, and germination. Often the coating, which increases the weight and size of the seed, is colored which aids in planting several varieties of seed in one tray, a row in a garden, or a field. 

While pelleted seed was originally developed for commercial production with a mechanical seeder. Then, seed companies began producing pelleted seed for vegetables and flowers and seeds are now available at local garden centers and big-box stores.

Photo by Mary Fischer. Pelleted seed are often sold in windowed seed packets.


Pelleted seed has been used intermittently since WWI. The improved pelleted seed was introduced for cereal seeds in the 1930s by a British seed company, Germains. In the 1940s, the U.S. used several types of pelleted seed in reforestation studies. The 1960s saw large-scale use of pelletized seed by commercial growers primarily for its ease of use with mechanical planters and new seed coating technologies. In the 1970s, California banned the use of short-handled hoes, increasing the use of pelleted or coated seeds.

Benefits of Pelleted Seed

Today, pelleted seed has many positive benefits for commercial productions and home gardeners. The coating protects seed from birds, rodents, and a wide range of environmental conditions that often lead to replanting. It reduces loss from needing to thin plants.

Precise spacing requires less seed, and since the seed is coated and visible, less seed will be used saving gardeners money. 

Photo by Mary Fischer. The brightly colored coating on pelleted seed makes it easier to keep track of which varieties you are planting when starting seeds.

For large-scale producers, it is easier for specific applications like aerial dropping or mechanical seeders. There are nutrient benefits with increased oxygen availability. The coating allows for pre-inoculation of legume seeds. Since chemicals are applied to the seed and not the whole field, application is safer and there is a lower cost of agricultural chemicals.

One obstacle to widespread adoption of pelleted seed has been the ability of the coating to split open once it is hydrated allowing oxygenated moisture to reach the seed. New levels of coating densities for commercial growers has overcome that issue.

Meghan Shinn has two precautions when using pelleted seed in a March 1, 2020 article from Horticulture Magazine. First, the growing medium needs to remain consistently moist, but not soggy, after the seed is sown. Secondly, all the pelleted seed must be used in the season it is purchased. This should not be a problem with most home gardeners as seed packets contain smaller amounts of seed.

How to Use Pelleted Seed

Pelleted seed is very easy to use. The colored coating allows a home gardener to see the seed as it is planted, the seed spacing, and where it is planted before covering with soil. If a home gardener is starting seed in a tray for transplant later, pelleted seed makes it easier to identify the different types of seed as it is planted.

How to Make Seed Tape

Another method of planting pelleted seed is to make your own seed tape. This is quite easy to do using single-ply toilet paper and glue.

  1. Simply tear off a length of toilet paper to fit the garden plot. Fold it in half lengthwise and cut into two pieces. Fold each length in half longways and open.
  2. Following the recommended spacing on the seed packet, place small dots of glue at the appropriate distance to one side of the fold, then add a seed.
  3. Once the entire length has been planted, fold the other side over the seed side.
  4. This tape can be wrapped around an empty paper towel roll and labeled for later use.
  5. When ready to plant, prepare the garden bed, lay the tape on the bed, and cover it to the proper depth as directed on the seed packet.

Article by Horticulture Educator Mary Fischer

Source: Gardeners Corner Spring 2022: University of Illinois Extension

Tips for starting your spring garden off strong

Cloudy, cold winter days may seem endless, but as the weather warms, bulbs will bloom and grass will green, giving way to sure signs of spring.

Grab your trowel and get ready. Spring is just days away.

Starting seeds

Keep in mind how last year the pandemic saw new gardeners flood garden centers and increase demand for products sold by online seed companies. Buy your summer-flowering bulbs, seeds and transplants early. Last year, many seeds and transplants were in short supply or out of stock. This spring, order your seeds early and purchase your transplants as soon as they are available.

It’s also important to avoid damping-off disease when starting seeds. Damping-off will cause seedlings to wilt and die. Use a pasteurized soil-less medium. Keep the temperature around 65 to70 degrees Fahrenheit for best germination and provide bottom heat if possible. Most of all, avoid overwatering. 

Soil preparation

Prepare the soil before planting. This means removing rocks and debris form the soil. Dig in a 2- to 4- inch layer of organic matter, which helps to breakdown heavy clay soils and improves drainage.

Never work your soil when it is wet. Tilling or digging when the soil is wet will cause it to dry into concrete-like clods.

Pick up a handful of soil before digging and squeeze. If it crumbles easily, it is ready to be dug. If it doesn’t, it is too wet. Allow the soil to dry for a couple of more days and test again before digging.

Late spring frosts

Be prepared for late spring frosts. Cover tender plants with row covers, cardboard, blankets, hot caps, or newspaper. Do not use metal or plastic for protection, because these can conduct cold to plants.

We have had frost close to Memorial Day in Illinois. The latest spring frost occurred in Rockford on May 27, 1992.

The growing season between the last spring frost and the first fall frost ranges from around 160 days to 190 days from northern to southern Illinois.


Buy healthy transplants. Leaves and stems should be green and healthy without any signs of yellowing or browning. Gently remove transplants from their pot and check the root system. Roots should be white with visible soil. Check for insects such as whiteflies or aphids. 

Harden off transplants. Before exposing transplants to cool, spring temperatures, wind and sun, gradually introduce them to the outdoor environment over a 10-to-14-day period. At first, place the transplants in a shaded area for a couple of hours. Gradually increase their exposure to sunlight each day until they are outdoors for 24 to 48 hours before planting.

Perennials and ornamentals

Divide perennials. Dig around the plant and lift the clump out of the ground. Break the clump into sections. Larger sections will re-establish quicker than smaller sections. Keep the clumps moist until ready to plant. 

Cut back. Cut back ornamental grasses to about 4 to 6 inches. Not removing the foliage will delay the warming of the crown of the plant and will slow new growth. Ornamental grasses should be divided in the spring if the center of the plant has died out or if it has become overgrown.

Article By Ron Wolford, Horticulture Educator

Source: Gardeners Corner Spring 2021: University of Illinois Extension

Are Your Garden Seeds Still Good? Here’s How to Tell

Don’t waste time and effort! Before you get growing, check to see if your seeds will germinate with these helpful tips.

Before you plant older seeds find out if they’ll still germinate with these helpful tips.

If you’ve started planning your spring garden, you might be taking stock and seeing what materials you have to work with. Are you wondering if the seeds you intended to use last year are still good? Or, what about those heirloom seeds you got as a wedding favor a few years back?

Just like most things in nature, seeds have a shelf life and you need to determine your seeds’ ability to germinate before you start planting. You don’t want to waste your time and effort!

Seed Viability – In A “Nutshell”

seedlings growing in dirt and sunlight

Most brand new seeds have a 90% germination rate, meaning that 9 out of every 10 seeds you plant should grow. But if you’ve got seeds that have been hanging around for three years, the germination rate drops to around 60%. That means you’ll need to plant a higher number of these older seeds to increase your chances of growing something.

Seed Viability Test For Older Seeds

If you have older seeds, it’s wise to do a quick viability test prior to planting when using older seeds. Here’s what to do:

It’s a good idea to test viability on older seeds.
  1. Fold a dampened paper towel in half.
  2. Take 2-3 seeds and place them on the damp towel.
  3. Fold the towel over the seeds and place them in a zippered plastic bag or airtight container in a warm location.
  4. After a few days, open the bag and take a peek to see if any sprouted. This will give you a good gauge of how your seeds are germinating.

If the germination rate is low, but there is still some viability (for example, maybe only 2 of the seeds in your test sprouted), simply plant more of those seeds in the garden, knowing that not all may sprout. You’re just increasing the sprouting odds.

If none of them sprout, obviously, you’ll have to purchase fresh seeds.

Seed Storage Tips

Heirloom seeds are often given as wedding favors!

The key to keeping your seeds viable for a few seasons is proper storage. Be sure to do the following:

  • Keep your seeds in a cool spot that offers a consistent temperature. Your best bet is to put them in a moisture-proof sealed container (if they’re already in packets, you can keep them right in the packets while storing) and store in your freezer or refrigerator. It is extremely important the seeds are 100% dry or mold will develop. You can even add some rice to the container to wick away any possibly moisture.
  • Keep them out of direct sunlight.
  • Keep them away from any humidity or moisture.

How you store them won’t only be for the long-term, it will be your day-to-day access while you’re outside sowing.

Storage Life Of Vegetable Seeds

Below is a list of the approximate lifespan of your favorite vegetable, herb, and flower seeds when stored properly. Keep in mind this is just an estimate—many seeds might be viable much longer, while others a bit shorter.

VegetableStorage Life
Asparagus3 years
Beans3 years
Beets4 years
Broccoli4 years
Brussels sprouts4 years
Cabbage4 years
Carrot3 years
Cauliflower4 years
Celery3 years
Chard, Swiss4 years
Chicory4 years
Chinese Cabbage (Bok Choy)3 years
Corn, Sweet2 years
Cucumber5 years
Eggplant3 years
Endive5 years
Kale4 years
Leek2 years
Lettuce4 years
Melon5 years
Mustard4 years
Okra2 years
Onion1 year
Parsnip1 year
Pea3 years
Pepper3 years
Pumpkin4 years
Radish4 years
Rutabaga4 years
Spinach2 years
Squash4 years
Tomato5 years
Turnip4 years
Watermelon4 years

Storage Life Of Flower Seeds

Seedlings in pot and seed packets, close up, isolated on white background
FlowerStorage Life
Ageratum4 years
Alyssum4 years
Amaranth3 years
Aster1 year
Baby’s Breath2 years
Bachelor’s Button3 years
Calendula5 years
Celosia4 years
Clarkia2 years
Coleus2 years
Columbine2 years
Cosmos3 years
Dahlia2 years
Daisy3 years
Delphinium1 year
Dianthus4 years
Foxglove2 years
Geranium1 year
Hibiscus3 years
Hollyhock3 years
Impatiens2 years
Larkspur1 year
Lobelia3 years
Lupine2 years
Marigold2 years
Nasturtium5 years
Nicotiana3 years
Pansy2 years
Petunia3 years
Phlox1 year
Poppy4 years
Salvia1 year
Snapdragon3 years
Sweet Pea3 years
Verbena1 year
Zinnia5 years

As a general rule, most annual flower seeds are viable for 1-3 years and perennial seeds for 2-4 years.

Article by Allison Vallin

Source: Are Your Garden Seeds Still Good? Here’s How To Tell – Farmers’ Almanac (farmersalmanac.com)