Hay Fever

Try Winter Sowing for a Great Garden Next Year

Amy HillMost gardeners look forward to winter as a time to rest, plan, and daydream about next year’s garden using the tempting seed catalogs that begin to fill our mailboxes in the holiday season. We don’t typically think of winter as a time to get our gardens started. But if your daydreams involve filling those annoying holes in the border where plants haven’t filled out as expected, or perhaps extend to creating that cutting garden you’ve always wanted, winter is the time to get started. If you have a seed packet, some seed-starting mix,  and a place outside where you can store a container, you can use winter sowing to get a jump on next year’s growing season.

winter sowing seed packets

Winter sowing is a technique that uses the plants’ own evolved mechanisms for reproduction. In the wild, plants reproduce by dropping seed onto bare ground, where it experiences the rain, ice, snow and temperature fluctuations of the dormant season. When spring arrives and temperatures begin to regulate, the seeds break dormancy and send out a radicle, or root hair, followed by seed leaves, called cotyledons. The plants carry on their life cycles without the intervention of a gardener.

Many plants, both annual and perennial, vegetable and ornamental, can be propagated using this technique. It can be done gradually, as the gardener has time. The best time to start is anytime after the winter solstice.

How to Winter Sow:

1. Repurpose containers found around your house. Plastic gallon or half-gallon milk jugs cut in half horizontally, takeout containers (clamshell or two-part containers with clear lids), and plastic tubs from prewashed salad greens make excellent winter sowing containers. Using a knife or pair of scissors, make several slits or holes in both the bottom and the lid of the container. The bottom holes provide drainage; the top holes allow water to penetrate while protecting your seeds from hungry foragers.

2. Using duct tape and a waterproof, permanent marker, label the contents of your container and apply the duct tape to the underside of the container. Doing so helps prevent sunlight from fading the label. Alternatively, use pencil and a store-bought seed flat label and stick the label in the soil mix.

3. Fill the container with soilless seed starting mix, available at garden centers and home improvement stores. Do not use potting mixes with weed control additives; those chemicals will prevent your seeds from sprouting.

4. Water the container until it drains freely from the bottom.

5. Sprinkle the seeds onto the soil surface. Very fine seed, such as that of foxgloves, perennial poppies, or lettuce, does not need to be covered. Otherwise, cover with a layer of soilless mix, sand, or vermiculite to the depth indicated by the seed packet. If you can’t find instructions, plant the seeds twice as deep as they are thick. Tamp them gently into the soil surface with your hand or the base of a pot.

6. Water gently again. The spray attachment to your kitchen sink works perfectly. Take care not to flood the seed. Cover the container with its lid.

7. Set the container outside in a spot where it will be exposed to the weather, but out of the way of most animals. The top of a picnic table makes a great spot, but the ground is just fine. Make sure the container is not protected by the eaves of your house, or it will dry out.

winter sowing - winter containers

8. Leave them alone until about five weeks before the average last frost date in your area, when the lids may be removed to allow seedlings to harden off completely.

winter sowing - winter sown lupines

If you fiddle with the containers in the meanwhile, you’re missing the point. The beauty of the winter-sowing technique is that it requires no further intervention by the gardener until spring, when it’s time to transplant. The seedlings will be naturally hardened off by their exposure to the elements. They’ll survive just fine without additional nutrients; the seed has all the nutrients the plant needs until it can photosynthesize on its own. Just settle down by the fire and get back to those catalogs.

Here are lists of just a few plants that perform well using winter sowing:

Hardy annuals:

  • Ageratum (floss flower)
  • Alyssum (sweet alyssum)
  • Antirrhinum (snapdragons)
  • Calendula (pot marigold)
  • Celosia (cockscomb)
  • Centaurea (cornflower)
  • Cosmos
  • Cuphea
  • Dianthus chinensis (China pinks)
  • Gypsophila (baby's breath)
  • Helianthus (sunflowers)
  • Larkspur
  • Mallow
  • Malva (mallow)
  • Nasturtiums
  • Nicotiana (flowering tobacco)
  • Pansies
  • Sweet peas
  • Tithonia (Mexican sunflower)
  • Torenia (wishbone flower) 

Perennials:

  • Aster
  • Astilbe
  • Bellflower
  • Blanket Flower
  • Blazing Star
  • Butterfly Weed
  • Coral Bells
  • Coreopsis
  • Coneflower
  • Foxglove
  • Hardy hibiscus
  • Hellebores
  • Hollyhock
  • Iris
  • Lily (Oriental varieties)
  • Phlox
  • Pincushion Flower
  • Pinks
  • Poppy
  • Red Hot Poker (Kniphofia)
  • Rudbeckia
  • Rose Campion
  • Russian Sage
  • Salvia (varies by species)
  • Sedum (varies by species)
  • Shasta Daisy
  • Verbena
  • Veronica
  • Viola
  • Yarrow 

Vegetables:

  • Alliums (onions, shallots, garlic, chives)
  • Artichokes
  • Asian vegetables
  • Beans
  • Beets
  • Brassicas (cabbage, broccoli, kale, collards, etc.)
  • Carrots
  • Celery
  • Celeriac
  • Chards
  • Corn (early types)
  • Cucurbit family (cukes, squash, pumpkins, melons, gourds)
  • Herbs (edible and ornamental)
  • Lettuces
  • Nightshade family (eggplant, tomatoes, peppers)
  • Parsnips
  • Peas
  • Radishes
  • Spinach
(Portions of this post from Trudi Davidoff at GardenWeb.com)

Grow Comfrey for a Perennial Source of Organic Fertilizer

Amy HillUsing commercial fertilizers, particularly sustainable or non-synthetic ones, can get really expensive. Compost and manures add important organic matter to the soil, which helps to build the subterranean ecosystems that support plant health, but they don't add much in the way of major nutrients.

Fortunately, nature has provided a means to make our own sustainable fertilizers. Comfrey (Symphytum officianale), a plant that grows well in most gardens, provides nutrient boosts when added to compost or used in liquid fertilizers. And once you've bought the plants, it's free.

Comfrey is a borage relative. Hardy to Zone 3, it has large, broad leaves like those of Pulmonarias, to which they are related, and small clusters of blue or white pendulous flowers. Comfrey's fuzzy, sometimes prickly leaves discourage insect pests. It grows in a range of soils in sun to part shade, and uses its impressive root system, which may grow anywhere from 6 to 10 feet deep, to mine minerals from the subsoil, aerate its surrounding soil, and break up the heaviest clays. It will regrow from tiny slivers of root, though, so be sure to plant it where you want it. If you are as indecisive as I am, grow it in a container. You won't get quite the same level of benefits as compared to comfrey grown in the ground, but at least you won't have it permanently installed.

comfrey and bee

Comfrey has been used in the past in herbal medicine, but research proves comfrey contains poisonous chemicals called pyrrolizidine alkaloids (PAs). The roots contain up to 10 times the amount of PAs as the leaves. Its toxic chemicals can be absorbed through the skin, though, so it is advisable to wear gloves when handling comfrey. Do not take any part of the plant internally, as it is extremely toxic to the liver and may also be carcinogenic.

For plants, though, it's a wonder food.

Comfrey contains high levels of the macronutrients nitrogen (N), phosphorus (P), and potassium (K), as well as calcium and vitamin B12. Comfrey also contains allantoin, a chemical compound that stimulates cell growth and regeneration. It may be the allantoin that makes comfrey so effective as a fertilizer. Extracts from comfrey's leaves have antifungal properties, and have been shown to effectively combat powdery mildew.

It's good to know the specific epithet of the plant you're getting. Symphytum officianale, the species, will seed prolifically and may become problematic in the home garden. The Bocking 14 strain of comfrey (Symphytum x uplandicum) contains the high nutrient levels of the species, but it's also sterile, so it won't self-seed and become invasive. Bocking 14 is difficult to track down in the United States, but is available from a few Internet sources.

Comfrey leaves can be used as a mulch or buried in the garden bed at planting time. As they rot down, they'll enrich the soil. Take care when using them as a mulch, though: The decaying leaves can be attractive to slugs, so don't mulch with them around leafy greens or ornamentals like hostas.

A more versatile way to use comfrey is as a liquid fertilizer or tea. To make the tea:

  1. Chop up a handful of fresh leaves (use gloves), and place in a container with a well-fitting lid.

  2. Add water to cover, submerging the leaves with a rock if necessary.

  3. Let the mix rot down for 3 to 4 weeks. At this time, the comfrey will have been reduced to a (very) stinky black goo.

  4. Dilute the comfrey liquid concentrate at a rate of approximately 1 part comfrey to 15 parts water. The final product should be light brown in color, like weak tea. Water it in around plants that need a boost, particularly fruiting plants, or use the tea as a foliar spray on plants that are susceptible to mildew.

  5. Seal up the rest of the concentrate for use at a later time, or bury it in the compost pile to supercharge your compost.

Comfrey tea is relatively higher in phosphorus and potassium, so you may wish to blend it with nettle tea to get a better nitrogen boost. This tea will feed the soil as well as your plants, ultimately making your plants more resilient. For a gentle, natural fertilizer, comfrey is hard to beat.

Photo of comfrey and bee courtesy of InAweofGod'sCreation/CC-BY 2.0.