Supergermination of Annual Weeds Possible by Irene Shonle

The torrential rains of last fall combined with an above average snowpack this winter mean that we can expect a banner year for weeds, especially annual weeds.  (Of course, it also means we should have a fabulous wildflower year, too.)

 

Cheatgrass 

Cheatgrass, also known as downy brome, is the weed that is most likely to be found in abundance this year.  Cheatgrass can outcompete most native plants and even many grasses, because it germinates so early; it is a state-listed noxious weed (List C).  Later in the summer it becomes a fire hazard and a nuisance as the seed heads lodge in socks and fur.  Cheatgrass can produce 13,000 seeds per square yard (meter).  When conditions are just right, almost all of these seeds will germinate, creating a larger-than-usual crop of weeds.   

Alyssum simplex (also known as Alyssum minus) at early stages of flowering -- a great time to tackle it

Small-flowered alyssum, that tiny upright weed that turns the hillsides a yellow green in the spring, will also respond to the moisture, but perhaps not quite to the same extent.  Other annual weeds that might respond enthusiastically include scentless chamomile and field pennycress.

This supergermination might sound like it’s really bad news, but it all depends on whether you can get out there to deal with them before they go to seed.  If you can, this spring will be a golden opportunity to deplete most of the seeds in the seed bank.  That means that in future years, there will be almost no new weeds!   If possible, prioritize working on these weeds in May and early June, especially if you don’t have extensive patches to deal with.  If your populations are large, try tackling the most important areas first; these probably will be the areas closest to your house, or where you want to grow flowers.  The flip side is that if the weeds go untreated, we will have extra seeds going into the soil and weed populations will increase.

The key here is in the timing – you have to get out there almost as soon as the seeds germinate.  If you catch them before there are any seeds present, you can hoe, till, or pull the weeds.    It’s possible to take care of huge swaths of weeds in just an hour using a stirrup hoe.  Kind of makes you feel like the Valiant Little Tailor of Grimm’s Fairy Tale fame, who “killed seven with one blow.”  There’s no need to bag the plants if seeds have not been set (anytime through early flowering); they can just be left to decompose on the ground.   It’s also possible to use an herbicide, but you would need to apply it very early; many annuals don’t respond to herbicides later in their growth cycle

 

Cheatgrass seedlings before flowering and seed set -- easy to take care of with a hoe

If you don’t quite catch them before they set seed, controlling the weeds becomes a little more of a nuisance, but is still doable.  Pull the weeds and seal them in a plastic bag, then throw them away.  Since this can quickly turn into quite a lot of bags, it’s easy to see why getting them earlier is a good idea.

Pulling and bagging cheatgrass

Cover Crops by Trudy Hodges

Winter Cover Crop

This past winter I decided to try growing some cover crops in my greenhouse.  I planted some white clover, and a few others (I can’t remember).  The photos were taken before I tilled the soil in preparation for planting.

Cover crops are amazing; they provide many positive aspects to the garden.  They can provide erosion control, fix nitrogen, and build soil quality.  Cover crops are also called “green manure” and are often in the Fabaceae (pea) family.

 

Clover Cover Crop

Increasing soil fertility is one of the primary uses of cover crops.  They can influence a range of macronutrients and micronutrients; nitrogen has received the most attention since it is often the limiting nutrient in crop production.  Cover crops can also improve soil quality by increasing organic matter levels when crops are killed and incorporated into the soil.  Plants must be killed before they go to seed and before the top growth gets too mature.

After plowing under the green compost it is best to wait 2 to 3 weeks before planting vegetables or flowers, as crop decomposition can tie up soil nitrogen.

At higher altitudes, cover crops can be planted as early as mid-September, with mid-October being the latest. Depending on your elevation, you may need to plant earlier to get the plants established before freezing weather. Do not let crops go to seed, or you will have cover crop in your seed bed.  Many of the crops winter kill allowing you avoid the waiting period in the early spring.

Buckwheat is a broadleaf plant that will smother out weeds and other plants.  Its flowers also attract beneficial insects.

Clover comes in many varieties.  Clover fixes nitrogen, attracts beneficials and helps build rich soil.  Clover must be inoculated with a Rhizobium bacteria for best results.

Rye comes as annual or cereal rye.  Annual rye will winter kill allowing you to skip the waiting period in the spring.

Field Peas fix nitrogen and are cold tolerant, making them a good fall plant.  They will winter kill, allowing an early spring start.

Seed Saving … Libraries, Banks or Exchanges?

Glorious Seeds - photo by Hannah Walters

Let’s clear up the confusion for first time seed savers or returning gardeners who aren't quite sure the exact and best approach to seed saving and expanding resources for this popular garden trend. It starts with the basic question – why save seed and how hard will it be?  The short answer to successful seed saving as well as access is we all desire clean, healthy foods from our garden that preserve biodiversity and provide for the continuation of pure heirloom vegetables that have been popular for ages but not necessarily viable for commercial farming.

Like many things, the difficulty lies in specific details. Seeds from hybrid plants are most likely not to reproduce exactly year to year due to their mixed genetic nature, so they are not desirable for saving. Heirloom varieties require needed attention to growing, cross pollination, collecting and storing of the viable seed.  Do your homework and start with knowing your growing zone and what specifics (cleaning winter refuse, soils, exposures, etc.) need attention in your beds before you plant anything for your vegetable garden.  Then plan your garden considering these added resources of seed, beyond your garden center or mail order catalog.

A Seed Library lends seeds or may even share seeds from an existing collection.  The primary element is the recipient grows out the seeds, saves from the plants then returns the seeds to further the library collection.  Many public libraries are starting seed collections for this purpose.  Be cautious to make sure they’re testing their seeds for viability and can provide standards on how seeds were stored.

National Center for Genetic Preservation, Fort Collins, CO

A Seed Bank is just that, a bank of seed reserves that have been housed to protect against destruction and also preserves biodiversity in case of disasters or other calamity. One exists at CSU in Ft. Collins in partnership with the Nat’l. Center for Genetic Research Preservation. In addition to the Bank, CSU also operates their own seed lab where vegetable, flower and native seed is tested for purity & germination.  You can visit their website at www.seedlab.colostate.edu for further information.

Seed Swap/Exchange at Organic Seed Alliance Conference 2014

A Seed Exchange is a group of interested parties coming together to offer seeds for exchange or trade while still having the ability to find specific seed varietals for their own needs.  This can happen in a neighborhood, or community group or even a garden club in a simple seed swap.

Soon through your local Master Gardeners with the Extension program in Jefferson County will have their own exchange and will be open to accept seed at the end of the 2014 growing season.  You can join the High Altitude Seed Exchange for a small fee, thus allowing access to seed grown and viable in altitudes of 5,000’ and above.