Thursday, September 21, 2017

Why Leaves Change Colors and the Autumnal Equinox by Carol King

Photo by Carol King
The Autumnal Equinox in Denver is Friday, September 22, 2017 at 2:02 p.m. MDT.  So just what is the equinox? There are two equinoxes every year (September and March) when the sun shines directly on the equator and the length of day and night is nearly equal. It occurs the moment the Sun crosses the celestial equator – the imaginary line in the sky above the Earth’s equator – from north to south. This happens either on September 22, 23, or 24 every year. 

Days are becoming “shorter”and the leaves are  “changing colors”.    According to Plantalk Colorado in actuality, leaves don’t change color, they just quit producing chlorophyll, the substance that makes them green.

This happens for a variety of reasons: shorter days, falling temperatures, available water.  These are all signals to the plant to go into energy saving mode and quit producing chlorophyll:  Winter is coming!

When chlorophyll breaks down, what’s left is the color that was already there:  Yellow/ carotenoids, and red /anthocyanin. These pigments are masked by chlorophyll but help protect the leaves from sunlight. After the equinox shorter and shorter days become the norm. The chlorophyll will totally disappear leaving us with beautiful colors for a short while and then dead leaves to deal with!

As you watch the leaves slowly change color and fall from the trees, you know the equinox is partly to blame.

Happy Autumnal Equinox and Happy Leaf Peeping!

Wednesday, September 20, 2017

A Visit from the Painted Ladies By Joyce D’Agostino

Photo by Joyce D'Agostino
Recently I noticed a large group of colorful butterflies on my fall aster plants. These butterflies are Vanessa cardui more commonly known as the Painted Ladies.
Due to favorable spring conditions in California, which helped these butterflies find the right host plants to lay their eggs, and then favorable weather and host plant conditions during the summer to aid in their nutrition, these colorful insects are numerous this year.  

Tuesday, September 19, 2017

Browning Evergreen Needles Normal by Mary Small

Photo by Carol King
Are your evergreens showing some browning and losing needles? Never fear! This is normal evergreen behavior.  It is not unusual for conifers to shed interior needles beginning in late summer and continuing well into fall.   In fact, all conifers (“evergreens”) including spruce, pine, fir, juniper and arborvitae lose their oldest needles every year. Contrary to what the name implies, “evergreens” are not really green forever. Their needles generally have a 2–4 year life span, although spruce trees live about 5-7 years. 

While needle loss occurs every year, the process is usually gradual, over a period of several weeks or even months, depending on species and weather. It’s so gradual, that you might not even notice the needle drop. Some species can shed needles in a fairly short period of time, making it look as though they’re in serious trouble. There is no need to treat evergreens for the condition.  

This fall and winter, ensure all evergreens are irrigated monthly in the absence of rain or snowmelt. Apply water so it reaches the absorbing roots.  For established plants, these are located a distance of two to three times the height of the plant away from it. For newly planted trees, apply water to the planting hole and just outside it. Always irrigate when the soil is unfrozen and able to absorb the water.  Studies show that fall-applied water has great benefit.  Roots are still active and can absorb water as long as soil temperatures stay above 40 degrees Fahrenheit.  

For more information about winter evergreen care check here.

Saturday, September 16, 2017

Fall Gardening Tips Video

Colorado State University Horticulture faculty and graduate students share their best inside information you can use in your garden.

Monday, September 11, 2017

Harvesting Amaranth by Donna Duffy

Amaranth ready to harvest, photo by Donna Duffy

You can begin harvesting amaranth plants for greens almost immediately. Young greens are perfect for salads, while older greens are better when cooked like spinach. Seeds ripen about three months after planting, usually in the mid- to late summer, depending on when you planted. They are ready to harvest when they begin to fall from the flower head (tassel). Give the tassel a gentle shake. If you see seeds falling from the tassel, it’s amaranth harvest time.

Thursday, September 7, 2017

It's Grape Harvesting Time by Donna Duffy

Candice grapes ready to harvest, photo courtesy John Crawford

Grape growers anticipate this time of year all season long. If Mother Nature has been cooperative, it’s finally time to take off the nets and harvest grapes. John Crawford, my neighbor in NE Lakewood, has been growing grapes and making wine for over three decades.

Monday, September 4, 2017

Got Milkweed? by Donna Duffy

Asclepias speciosa seeds about to disperse, photo by Donna Duffy

If you have  native Milkweed (Asclepias speciosa) plants in your landscape, now is the time to decide how many more you want. Milkweed seed pods are bursting open and each one releases numerous seeds that love to drift to other parts of your yard and take root. That’s great if you want more Milkweed plants! But if you don’t, now is the time to take action.

Friday, September 1, 2017

Bee Flies in Colorado By Joyce D’Agostino

Bee fly on Lobelia, photo by Joyce D'Agostino

This summer while I was observing some bee activity on my flowers, I noticed an unusually fuzzy insect that was foraging for nectar. I was curious what it was so I sent a picture of this ‘bee’ to Mario Padilla, Entomologist at the Butterfly Pavilion. Mario specializes in bees but is also widely knowledgeable in the genus and species of many native and exotic insects.

Monday, August 28, 2017

The Benefits of Planting a Fall Cover Crop by Jennifer Verprauskus

Hairy Vetch cover crop, photo courtesy Urban Farmer Seeds
When Fall rolls around and everyone starts to put their gardens to bed, there are a few things to consider before you say good bye to the garden until next spring. It’s during this time of year that we have the choice to either plant a fall garden or a fall cover crop. 
The fall garden is typically started at the end of July or early August but it can be planted into September and October. In early to mid-October, we can replant spinach, cilantro, arugula, asian greens, kale, and other fast growing semi-cold hardy crops. However, when I plan on planting this late into the Fall, I think about using a season extender, which is a structure that captures heat from solar radiation and warms the plants and soil inside the covering, such as low hoops, heavy weight Reemay, cold frames and much more.

Sunday, August 27, 2017

Cicadas: The Sounds of Summer's Close by Carol King

Dog Day Cicada (Tibicen dorsatus, T. dealbatus) photo by BugGuide.Net
Nothing signals that August is here like the sound of cicadas singing: they can be counted on to sing until frost. In fact, according to folklore, it's six weeks after the first song that a frost is possible. Here are some other interesting facts about cicadas:

Cicadas are essentially tiny violins with wings. The body of a cicada is similar to that of a violin or a guitar, in that much of it consists of empty, air-filled spaces that act like a resonating chamber and amplify the sound they generate. The loud noise we hear is the male's mating call—females are silent.

Cicadas are the loudest insects in the Southwest. Their mating call and response can reach over 90 decibels. That is as loud as a gas lawnmower or a motorcycle. 

Cicadas are super sneaky. Ever tried to locate a cicada you are hearing, only to find nothing there? Once you start walking to a tree they stop calling as soon as you get too close, making it even more difficult to find them.

Cicadas have enemies that are the stuff of nightmares. The female cicada killer wasp flies around,  finds a cicada, stings and paralyzes it, and carries it to a burrow, lays one egg on it, and then closes the burrow up where the larva proceeds to feed on the victim.

There are 26 species of cicadas native to Colorado. The most common one along the Front Range is the Dog day cicadas (Tibicen dorsatus, T. dealbatus), the largest cicadas found in Colorado. They may be upward of two inches long. Their common name is derived from the males’ piercing call, which is often heard in the so-called “dog days” of mid-summer.

Friday, August 25, 2017

Harvesting and Enjoying Sunflower Seeds By Joyce D’Agostino

Photo courtesy Donna Duffy

Sunflowers are one of the most popular and recognized parts of American gardens. In addition to their bright beauty, they attract beneficial insects. Some species produce seeds that are not only a great snack but have good nutritional value.

This time of year, most sunflowers are in bloom and some are already producing their dried discs of seeds. There are several varieties of sunflowers now available to the home gardener. These include pollenless flowers that have been developed for cutting bouquets. This type does not shed the yellow pollen onto furniture or cause issues for those with pollen allergies. There are dwarf varieties, also preferred for flower bouquets, as well as specialty color combinations.

Tuesday, August 22, 2017

Proper Soil Drainage Helps During Monsoon Season By Joyce D’Agostino

Gardening in the rain! Photo courtesy

Gardeners in the front range of Colorado often find themselves during the summer growing season with hot temperatures and little rainfall or watering restrictions. This month we experienced the opposite effect with monsoon effect storms. While the moisture is welcome, often these storms produce very heavy rain in short periods of time supersaturating the soils and can include high winds and hail.