Friday, September 30, 2016

Put Poinsettias in the Dark for Reblooming by Carol King

Photo by Carol King
So you saved your poinsettia from last Christmas. You fed and watered it properly and it’s looking good.  Right now is the time to take action give it some uninterrupted darkness if you want “blooms” by this holiday season.

Photoperiodism is the physiological reaction of organisms to the length of day or night. Poinsettias are short-day photoperiodic plants. They actually sense seasonal changes in night length which they take as signals to flower. This means they set buds and produce flowers as the autumn nights lengthen, blooming naturally during November or December.

Starting about October 1, your poinsettia needs at least 14 hours of uninterrupted darkness each night at temperatures between 60 and 70F.  Stray light of any kind (street lights, pool lights or lamps) could delay or entirely halt the reflowering process.  From October 1 to December 1, (or for at least 40 days) your poinsettia will need a strict light/dark regimen to produce color. Provide 13 to 16 hours of complete and uninterrupted darkness daily. At dusk, place the plant in a dark room (or closet) or cover with a box or paper bag.  At dawn, move or uncover the plant to allow 8 hours of sunlight. The dark treatment should last until color shows in the bracts (approximately Thanksgiving). Continue fertilizing and watering to encourage good growth.

For more information about the care of poinsettias look here:

Monday, September 26, 2016

Try Growing Leafy Greens to Provide Ongoing Winter Nutrition By Joyce D’Agostino

Photo by Joyce D'Agostino
The summer is winding down,and for many that means the end of gardening season.  There is good news, however, for those who want to try to extend  harvests into the cooler weather and to try some new methods.
Many of the vegetables commonly called “greens” such as spinach, kale and collard greens enjoy and even get better tasting with the cooler weather. It’s well known that these leafy greens pack a lot of nutrition, and can be enjoyed in salads, prepared as a side dish or added to smoothies.
With a little protection such as frost blankets, floating row covers or plastic tents, these plants can go well into the colder months and possibly even provide ongoing harvests well into early winter. Planting them now allows them to establish their roots and begin growing their leaves for sturdier plants. Other great vegetables to try that tolerate colder weather and shorter days are root crops such as carrots, beets, kohlrabi and turnips.
For the most part, the fall into the winter gardening is more of a harvesting time rather than seeing plants getting bigger and producing ongoing fruits and vegetables. One good reference book to read on this topic is Four Seasons Harvest” by Elliot Coleman. Coleman began experimenting growing into the colder seasons on his Vermont farm and has some valuable tips for trying this in your own home garden. He explains that the colder months are more for harvesting what you have sown weeks before and how the proper protection and cultural practices keep the harvests going.
Here are some research based references for spinach and kale that give you tips on starting and growing these delicious greens this fall and winter:

Friday, September 23, 2016

How and When to Harvest Winter Squash and Pumpkins by Carol King

Photo by Carol King
Winter squash and summer squash are two separate vegetables to be handled differently.

Summer squash varieties include zuchinni, yellow squash and patty pan and are harvested and eaten as immature fruit.  Summer squash has soft, thin skin that is edible, can all be eaten raw or cooked, and has a mild flavor that can range from sweet to nutty. 

Winter squash varieties include acorn, butternut, hubbard, spaghetti, turban and of course pumpkins. They are harvested when the seeds within have matured fully and the skin has hardened into a tough rind. Winter squash are picked in September or October, before heavy frosts. Mature fruits can be stored most of the winter if protected from freezing. Immature squash and pumpkins do not store well; therefore, be sure that fruit is mature before harvesting.

To harvest and store winter squash and pumpkins follow these guidelines:
  • Pick winter squash when the skin has hardened into a tough rind not easily dented with light fingernail pressure. 
  • Harvest the fruit by cutting it off the vine with a sharp knife or a pair of looping shears leaving 3-6 inches of the stem attached to the fruit. 
  • Wash the fruit with soapy water containing one part of chlorine bleach to ten parts of water to remove the soil and kill the pathogens on the surface of the fruit. 
  • Make sure the fruits are well dried before setting in a shed to cure.
  • Winter squash can tolerate light frost that kill the vines.
  • Squash are best stored at a temperature between 50 and 55°F. Put the fruits on a single layer on wooden pallets with enough space in between them (the squash should not touch each other) and do not place them on a concrete floor. Store the fruits in a cool dry place.
For more information about harvesting and storing winter squash check these out: 

Wednesday, September 14, 2016

Is it your time? Become a Master Gardener! by Amy Bubar

Jefferson County Master Gardeners ready to serve!
Do you love planting those first little seeds in the ground each spring, eagerly awaiting their subtle greenery to break the soil surface? Do you have an on-going quest for knowledge? Do you enjoy helping others in your community?  Are you ready for the next step in your own back yard gardening?  If the answer to any of these questions is yes, consider becoming a Master Gardener! 

Monday, September 12, 2016

Don't Put Your Lawn to Bed Yet! by Rebecca Anderson

Photo by Donna Duffy
With fall approaching, everyone is looking forward to a break from the hot weather and summer yard chores of mowing and watering.  It's true that the grass isn't getting tall as quickly as it did in June, but that doesn't mean that it has quit growing.  In the fall, grasses are forming tillers: side shoots that thicken the grass and help it recover from losses that occurred in the more stressful times of summer. This side growth still requires some water, so don't roll up the hoses or blow out your sprinklers yet.  Water application of 0.5 to 0.75 inches per week is recommended by CSU for the months of September and October.  This is significantly less than the recommended 2.25 inches per week in the hottest months of summer, but is still more than our rainfall totals for most weeks. 

For some lawns, fall can be a good time for fertilizer application. Only green, growing lawns of cool season grasses (bluegrass, ryegrass, fescue) will benefit from fall fertilization. Warm season grasses (buffalo grass, blue grama, zoysia grass, Bermuda grass) should not be fertilized after September 1. Fertilizer needs to be watered in with 0.5 inch of water after application, so if your community is implementing a watering cut-off day, make sure the fertilizer is applied before that date. If your lawn has already gone dormant and is brown, fall fertilizer won't help much.  It is better to wait until spring. Check out the fact sheet on Fall Lawn Fertilization of for more information.

Saturday, September 10, 2016

Ripening Green Tomatoes Before First Frost by Carol King

Photo by Carol King
Tomato season is almost over and there are only a few weeks left before frost. (Average first freeze date in Denver is October 7).  Now is the time to start thinking about dealing with green tomatoes. 

Here are a few tips to speed-ripen on the vine:
  • Stop watering. This encourages ripening.
  • Root prune the plant. Dig into the soil 6-8” deep and cut around a circle 12” from the stem. Shake the plant but don’t dig it up. This will stress the plant and the fruit will ripen faster.
  • Pinch off any flowers, small fruit, new shoots, and suckers. Newly setting blossoms, small and very green fruit won’t mature in the remaining growing season and are best pruned off. It’s too late for them to become anything. Do this now and all the plants energy will go toward ripening.
  • When the fruit set is heavy, try removing some of the mature green fruit to ripen what’s left on the vine. Ripening numerous fruit takes a lot of energy from the leaves and tends to delay the whole crop turning red.
When frost is expected, try these:
  • Cover the plant completely and anchor so the wind doesn’t blow it off. Use old blankets, thick plastic, or anything similar and make sure it goes all the way to the ground providing the plant with trapped warmth.
  • Harvest the tomatoes by pulling the plant from the ground and hanging it upside down in a garage or other shelter. Check often for ripe ones.
  • Pick the pink ones and put them on the counter to ripen
  • Pick the green tomatoes and store them in a shallow tray lined with newspaper. They need 60-70 degrees and no light. The warmth ripens them not light.    
  • For more information, try these Fact Sheets:
Photo by Carol King

Wednesday, September 7, 2016

Plant Pansies in the Fall! by Carol King

Photo Carol King
Fall is the perfect time to plant pansies again. In fact, pansies and violas or Johnny jump-ups can be staples of the fall garden. These plants, both from the genus Viola, prefer cooler weather and struggle in the heat of summer. 

Pansies have a colorful past with lots of folklore about them.  One of my favorites is this one about why they have no odor: “A German fable tells of how the pansy lost its perfume. Originally pansies would have been very fragrant, growing wild in fields and forests.  It was said that people would trample the grass completely in eagerness to pick pansies. Unfortunately, the people’s cows were starving due to the ruined fields, so the pansy prayed to give up her perfume. Her prayer was answered, and without her perfumed scent, the fields grew tall, and the cows grew fat on the fresh green grass.”  {from Wikipedia).

Pansies are easy to grow in both pots (in potting soil medium) and in the ground. With some luck and judicious mulching, they can last clear through the winter into Spring!

Sunday, September 4, 2016

Fall: The Best Time to Sow Native Plant Seeds by Donna Duffy

Tradescantia occidentalis, Western Spiderwort, photo by Donna Duffy

There are many benefits to using native plants for Colorado home landscapes. They are naturally adapted to our various climates, soils and environmental conditions. When correctly sited, they make ideal plants for sustainable landscape. Native perennials require less maintenance such as watering and fertilizing when the planting site mimics the plant’s native habitat.

Thursday, September 1, 2016

Early September in Your Garden by Donna Duffy

Photo courtesy
It’s September, and Colorado gardeners are busy harvesting their vegetables and enjoying the last blooms of summer. Before all the fall gardening chores kick in, here are some simple September tasks to tackle.