Thursday, August 27, 2015

Top myths about noxious weeds By Irene Shonle

Noxious weed- Canada Thistle

Summer’s heat brings many things, both good and bad. The snow melts, opening up the high country for hiking, the flowers bloom, the birds sing and make nests, the pine pollen flies, the mosquitoes bite, and the noxious weeds begin to show themselves.
Noxious weeds are defined by the state, and are alien (not native) plants that cause problems for agriculture and ecosystems. Because they arrive in this country without the insects and diseases that help keep them in check in their country of origin, they have a competitive advantage over our native plants, and can cause species extinction on both local and global scales.
 Here are some of the top misconceptions about noxious weeds I’ve heard: 
1.   “Noxious weeds are medicinal plants.” A particularly pernicious misconception around here is the confusion between Musk thistle (Carduus nutans), which is a noxious weed with no medicinal properties, with Milk thistle/Blessed thistle (Silybum marianum), a plant that has been used medicinally for centuries, but does NOT grow wild around here. Scentless chamomile has none of the properties of Roman or German chamomiles.  It is important to be careful about which plants we actually have. For one thing, the person who collects musk thistle will be disappointed by its lack of liver-protecting qualities. For another, it is imperative that we correctly identify any plants we intend to control (there are also native thistles that should be protected). Granted, there are some noxious weeds with medicinal properties (St. Johnswort, mullein, tansy, chicory, wild caraway, and burdock), but they are small percentage of the rest of the state noxious weeds with no medicinal purposes. Further, most of the ones I mentioned are on “list C” of the noxious weed list, which means that they are widespread overall, and less efforts are put towards their control.  These weeds will likely be around in perpetuity for anyone to wildcraft, and I encourage people to harvest as much of them as they like (just please pull the roots, too, and make sure the weeds have not been treated with an herbicide). 
Noxious weed- Mullein

2. Noxious weeds somehow ‘heal’ the land.” I believe this myth has its origins in permaculture, and there is quite a rift in the permaculture community about noxious and invasive plants. While noxious weeds do get a foothold in disturbed and bare land, they can also quickly invade intact ecosystems, reducing biodiversity and changing ecosystem function. We have plenty of native plants that, were there no noxious weeds to get there first, would fill in the bare spots and do a far more effective job. These are called “pioneer species,” and bee plant, gumweed, tansy aster, scorpionweed, and some grasses are examples. Unlike noxious weeds, these pioneer species often act as ‘nurse plants’, harboring and protecting seedlings of longer-lived later successional plants.  
3.      “We cause more harm treating weeds than leaving them alone.” Noxious weeds grow rapidly (8-12% per year or more), and reduce biodiversity. Where oxeye daisy, Canada thistle, leafy spurge, and the knapweeds grow, few of our native flowers can make it. And native plants are what support our native pollinators – if we want to protect these critical species, we need to preserve the plants that support them. We must also consider the birds, elk, rabbits, deer, etc, that all depend on native plants. Weeds can be controlled by pulling, sometimes by biocontrol, and with herbicides. I know herbicides get a bad press, but I have visited many sites where the noxious weeds were controlled with herbicides, and I have seen firsthand the return of diversity and a flourishing ecosystem. Yes, herbicides must be used judiciously and strictly according to label, but they can be a very effective tool, especially when there are too many weeds to control by hand, or the weeds have deep root systems.
Noxious weed- Oxeye daisy

Monday, August 24, 2015

Interesting Lettuce and Salad Greens for the Mountain Garden by Sharon Faircloth

You will probably laugh, but I love growing lettuce!  Weather is obviously a big factor but continuous harvest and reseeding will keep you in nutritious greens almost year around. The key is to protect them from extreme cold and heat by using floating row covers and netting. There are many varieties that work well at altitude.

I prefer the red and green leaf lettuces to head lettuce.   Curly endive, arugula, mache and mesclun varieties are a bit different and add color and interest to salads.  I also like to throw in a couple of herbs and edible flowers to the bed.  This year I tried pennyroyal (Mentha pulegium) and I always love nasturtiums (Nasturtium officinale).  Both deter pests and nasturtium is fabulous for color (bright orange red and yellow) in the garden and delight in a salad.  Nasturtium are a member of the watercress family, have a light peppery flavor and make your salad look like it came out of a gourmet’s kitchen!  Pennyroyal, a member of the mint family, spread well, and did a good job keeping down the weeds.

To find the varieties I preferred to buy seeds with several different types, often called a salad blend.  Watching them grow, you can determine what is most flavorful and prolific.  It’s a good plan to always find choices with the shortest maturity dates but lettuce is such an instant gratifier that it sprouts almost overnight! 

This year I tried a new variety of romaine lettuce called “Freckles” which was fun.  It tolerated summer sun very well, stayed crisp and its red and green freckly color was an addition to the garden.  The watercress wasn’t as successful.  It was planted in a bed that wasn’t covered and it clearly didn’t grow as well.  I think the light was OK but it got way too much rain (did I just say that?) so grew more slowly than I think it should have.  I look forward to trying it again in a different bed.

Growing lettuce is pretty easy if I can do it; just protect it from all elements, harvest often, and enjoy your bounty.  Pick right before you plan to eat, as some varieties will be a bit limp if harvested too long before serving.  Taste is good but texture isn’t as appetizing.  Try something new you’ve never eaten before and I promise you’ll be happy.  If you don’t like it, I bet you have a friend or neighbor who will.  I recently visited the Boulder Farmer’s Market and saw bags of salad greens very similar to the varieties I listed above.  Imagine how pleased I was with myself seeing how much the farms were charging for “my crops”!!!
For information on the health benefits of home grown lettuce and pictures of many varieties, check out CSU Fact Sheet 9.373.  General info on all leafy vegetables can be found in Planttalk 1820.

Thursday, August 20, 2015

CHICKWEED by Elaine Blackmer

Stellaria media, or chickweed, is a potential problem for any gardener, whether you are hoping for an attractive lawn, or a healthy flower bed or vegetable garden.  If you spot this weed in your garden, you are likely to think, “What an attractive little plant.”  And that is definitely true, Chickweed is a dainty, low-growing annual with little heart-shaped leaves and abundant tiny white flowers.  Unfortunately, these characteristics lead many gardeners to ignore this little weed.
How could this little plant be such a problem?  Chickweed is incredibly invasive.  It grows densely and its long pliable stems work their way around and through the other plants, forming a dense mat of vegetation which smothers other plants and takes up the available resources.  Once it takes hold in your garden, it is difficult to eradicate, not just in this season, but for years to come.

Chickweed has a growth cycle of five to six weeks.  One plant can produce 800 seeds, and these seeds germinate immediately without a dormancy period.  And remember, new seeds are being produced every five to six weeks!  It takes 7 – 8 years for that seedbank to be depleted.  Are you beginning to see what we are up against?

About five years ago some chickweed landed in the planters across the front of my house.  Yes, I thought it was cute and I ignored it for a few years, until it became so vigorous and abundant that it was smothering my garden.  Thinking I could get rid of it, I pulled and dug out handfuls of it, but it made no difference, as pulling breaks the plants, leaving seeds and rooted plantlets.  It finally became so dense that anything planted was soon withered and dying.  Out of desperation, I covered the bed in black plastic for two years – guess what?  Didn’t make any difference.

Then I let the ground sit fallow for a whole year.  This June, I didn’t see any chickweed, so I put in some Marigold seeds, hoping they would be tough enough.  I watered the bed, and look what came up:
Help! What to do?  I wrote to CSU Extension and they recommended 1) Chemical herbicides, and 2) Take out all the soil and replace it.  Well, I don’t use chemicals, and removing all the soil really wasn’t feasible.  So here is the plan I used:
I mixed up an organic weed killer suggested  to me by another Master Gardener:  2 Quarts White Vinegar, 2 cups Epsom Salt, ½ cup Blue Dawn.  I watered the beds and let a crop of seedlings come up, then I sprayed them with the formula.  When those seedlings were dead, I watered and sprayed again, pretty much every week.  When I started July 1st, they were so dense you couldn’t see the soil; now in August, they are less prolific but still present.

Will I eliminate all the seeds this year?  Hard to say.
Be smarter than I was, don’t let this cute little weed take hold in your garden!