Monthly Archives: December 2016

Tweaking Tomatoes Produces Faster Fruit

tomatoesNew research in plant biology has the potential for earlier and larger harvests of sweet cherry tomatoes. The question is, would you eat a tomato that’s been tweaked?

Scientists are experimenting with Sweet 100 tomato plants to fine-tune genes and speed up flowering and fruiting. Scientists have found these tomatoes grow bushier plants that produce ripe tomatoes faster by several weeks. A report on the research appeared in a recent article published in Nature Genetics.

The research, conducted at the Cold Spring Harbor Laboratory in Cold Springs Harbor, N.Y., engineered mutations to “cause rapid flowering and enhance the determinate growth habit of field tomatoes, resulting in a quick burst of flower production that translates to an early yield.”

It all has to do with changes to the plants that eliminate day-length sensitivity. The lab provides more details about its research in this press release.

The technology scientists use for modifying plants is known as CRISPR (pronounced crisper). The acronym stands for clustered regularly interspaced short palindromic repeats – a precise laboratory method for editing plants’ genes. Because these plants contain no foreign DNA, they aren’t genetically modified organisms (GMOs).

In addition to harvesting earlier tomatoes, gene editing may help grow larger yields of crops and lead to crops that resist drought and diseases. Some current applications include a fungus-resistant wheat and larger harvests of rice. Gene editing technology may also allow some crops to grow in places where they wouldn’t normally thrive.

While gardeners are always interested in getting ripe tomatoes to their tables faster, do you think there are any potential downsides to this new technology?

By Jodi Torpey
A Denver Master Gardener

The Joy of Ornamental Grasses.

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It is December and finally winter has arrived in Denver!  Who hasn’t noticed the low winter light catching the grasses and adding a glowing soft orange to the otherwise monochromatic landscape. Perhaps now is the time to dream of growing grasses or sedges in your own unique space.


Beautiful Denver Home Enhanced with Winter Plantings

Grasses are adept at growing in different environments within the city.  Read labels carefully so as not to buy a “cool season” (perennial here)  whose growth, or requirements, do not meet your needs.  There are many cool season grasses that may take a few years to reach their maximum height (some formidable!). Also, establish that you are not buying a self-seeding variety if you want control. Also, check the details and ascertain that the water requirements can be met.  Remember even the most water frugal plants need help to establish.

Also, consider if you would like “warm season” (annual here) grasses too.  I bought a beautiful Red Fountain Grass Pennisetum setaceum at the CSU Extension Plant Sale, which is still pretty in December snow. This annual could have been overwintered indoors, but I took the lazy route and I like the golden winter interest that remains.

Grasses are invaluable in restricted spaces.  For example: rooftop gardens can be made into wonderful living areas with miniature grasses like a Hybrid Idaho Fescue  Fistula ‘Siskiyou Blue”, or perhaps a sedge like Ivory Sedge Carex eburnea.  Or large grasses can make dramatic modern statements. The delicate structure of grasses contrasts beautifully with concrete or other urban materials. Also, the narrow leaves are tolerant of high winds and brutal summer roof-top temperatures.  If you are using pots I would consider wrapping containers in burlap or another insulating material during the winter.


Some cool season grasses that fill in small space front garden varieties include: Dwarf Fountain Grass Hameln Pennisetum alopecuroides ‘Hameln’ and  Atlas Fescue Fistula mairei.  These make great border plants . For more dramatic focal point grasses the CSU Extension has a wonderful list to gather more comprehensive ideas as you dream for next year. CSU Horticultural Extension: Ornamental grasses information and list of plants.  

If you have the luxury of more land and you would like some self sowing varieties  the Indian Rice Grass Achnatherum hymenoideds looks lovely in the low winter light. The now wintery soft brown Blue Grama Bouteloua gracilis (our state grass!) is a casual signature planting that spreads prodigiously, and helps make the winter Western landscape warm and magnificent.

Some large grasses can get messy in the wintery weather but there is a solution if you don’t wish to cut back in fall or winter. Gardener Dave wrote a good piece in the Jeffco blog about controlling tall grasses, through the winter, so that they stay attractive and can then be left for cutting back until spring Click here for large grasses that can be maintained as structural interest in winter.

Anne Beletic CMG


Christmas Cactus Care


Let me start by saying I’ve killed my share of houseplants, but one that has lived for close to three decades is the Zygocactus. Commercially, growers sell two slightly different plants as Zygocactus: the Thanksgiving cactus which has pointy edged branch segments and blooms around turkey time and the Christmas cactus which has rounded segments and blooms for its namesake. Care for the plants is essentially the same. Mine, shown above, is the Thanksgiving variety, Schlumbergera truncate.  Through periods of  neglect, inconsistent feeding and infrequent (twice maybe?) repotting, this plant keeps blooming prolifically year after year. I’ve rooted cuttings several times as gifts, but curiously, its offspring have rarely flowered in their new homes, where I might add, they get more TLC than they would living with me. This begs the question, what does this plant need to thrive and re-bloom? Here are the best tips from the experts and a few of my own observations.

  • It likes a bright, but not sunny location with temperatures that do not drop below 60 degrees.  Mine moves from indoors to an east facing screened porch from Memorial Day till Labor Day, or longer if the fall is mild like it was this year.
  •  It is a cactus which likes humidity. Unlike most cactus which prefer dry air, it hails from the tropical rainforests of South America and likes moist air. Sitting the plant on a pebble tray with water that does not touch the bottom of the pot can help, or living in a kitchen or bathroom would be ideal.
  •  It wants good drainage. If repotting, use standard, well draining potting soil. Water when it is dry just below the soil line, about once a week. I’ve  found  it amazingly forgiving if  when I forget to water. Over-watering will cause branches to rot, so more is not always better.
  • Spring and Summer are its active growth times. Prune when it is done blooming or in early summer to promote side branching. Cuttings can easily be rooted in water or soil. Adding houseplant food during the growth period helps. I have cut back branches to about six inches in the spring and the plant tripled in size by the end of the summer.
  • Here’s the key! It needs longer autumn nights to rebloom. Photoperiodism is a plant’s reaction to periods of light, similar to our circadian rhythm. Starting in mid to late September, the Zygocactus needs between nine and twelve hours of uninterrupted darkness each day in order to flower. Thanksgiving cactus take about six weeks of longer nights to sprout buds, Christmas cactus need about eight to twelve weeks.  This longer “sleep” period is the trickiest part of the reblooming process and why the porch, which is generally dark at night, works so well. Other options are to locate the plant in a similarly lit room, or  early each evening, cover it with a box or put it in a closet. Complete darkness insures maximum blooms. From experience, I’ve found that the occasional interruption of darkness reduces blooms, but will not thwart all flowers.
  • Stop the longer night process when buds emerge. The plant is now ready to flower. At this time, reduce watering slightly to promote brighter flower color.
  • Watch for bud drop. This could indicate you’ve reduced water too much. If the plant is new to you, it also could be reacting to a change in environment. Drafts or temperatures below 60 degrees may also be the culprit. I often see shriveled tiny buds at the end of the blooming cycle, as though the plant is  exhausted from the work it takes to flower for weeks on end. I found no science to support this notion, just my take on it!

Zygocactus are graceful, pretty plants, with or without blooms. Their showy, colorful holiday flowers are a beautiful treat at the end of the year. With a little extra care in the fall, they will regale you with splendid  holiday color.

By Linda McDonnell, a Denver County Master Gardener