Monthly Archives: January 2017

Starting Seeds Indoors

It’s only January, but seed catalogs are arriving in the mail and gardeners are dreaming of summer. One way to get a head start on your vegetable garden is to start your own seeds indoors. It is relatively inexpensive to create your own seed-starting set up. In the long run you will save money because seeds are cheaper to buy than plants. If you want to take it a step further, you can save even more money by saving seeds from your favorite plants to start next year.

One of the great benefits of starting your own plants indoors is the amazing variety of seeds available at garden centers and in catalogs.  It’s great fun on a cold, snowy day to browse seed catalogs and find new and interesting varieties of your favorite vegetables to start for your garden.

Each type of seed has its own germination and growing requirements, but most seeds need to be started 6 -8 weeks before they will be planted in the ground.  To get seeds to germinate, you will need adequate light and soil temperatures above 70 degrees.  A warm sunny window may be adequate, but to ensure good germination and sturdy plants some extra help is often required. Cool soil temperatures and too little light will result in poor germination and spindly, weak plants.

To provide good light, use two four-foot florescent shop light fixtures suspended close

Shop light suspended from chain.

Shop light suspended from chain.

over the seedlings. The key to using florescent shop lights is to have one cool white and one warm white tube in each light fixture.  The combination provides the proper light spectrum for growing plants. Keep the lights on for 16 hours a day using a simple light timer. To avoid leggy, weak plants, keep the lights very close to the tops of the plants. This can be accomplished by hanging the lights from chains that you can adjust up or down.

To get the seeds to germinate you will need a warm, moist (not wet) environment. To ensure the proper environment for germination, use peat pots placed in seed starting trays with clear plastic covers.

Seed tray and clear cover

Seed tray and clear cover

The plastic covers keep the peat pots warm and moist until germination. Use a seed starting soil mix in the peat pots. Regular potting soil and soil from your garden are too heavy for starting seeds. Most seeds need soil temperatures of 70 degrees or above to germinate. To ensure adequate soil warmth, use heat mats under your seed starting trays.

Heat mat for starting seeds.

Heat mat for starting seeds.

Once the seeds have germinated and are growing, the heat mats and clear covers should be removed. The trays, covers, pots, starting mix and mats are all available at local garden centers.

Partial set up showing on light fixture.

Partial set up showing one light fixture.

Two four-foot shop light fixtures placed side by side fit perfectly over two standard 10.5” x 21” seed starting trays set end to end. Each tray holds 32 – 2.5” peat pots.

As the seedlings grow, raise the lights little by little to keep them just above the plants. Water just enough to keep the peat pots moist, but not soggy. The pots should not be sitting in standing water. Too much water will lead to poor germination and weak plants. You can also use a spray bottle to mist the plants to add moisture.  Once the plants are growing and develop true leaves, a weak solution of a Miracle-Gro type fertilizer will promote strong plants. Put two or three seeds in each peat pot to make sure at least one plant germinates per pot. As the plants grow,

Trays under lights after germination.

Trays under lights after germination.

keep the strongest plant in each pot and thin by snipping the weaker seedlings near soil level.  Always snip, don’t pull. Pulling out the weaker plants can disturb the roots of the remaining strong seedling.

Happy plants.

Happy plants.

About two weeks before you plan on putting the plants in the ground, start hardening off the plants by placing them outside for part of the day. Start off slowly! The leaves will be tender and susceptible to damage from too much sun or wind.  Start with a few hours in dappled shade on a mild day. The daytime temperatures should be above 55 degrees. Day by day, the plants will become stronger and can be left out longer and in more direct sun. Do not leave them out overnight if the temperature will dip below 50. Peats pots are small and can dry out very fast.  Make sure the plants have adequate water while hardening off. One way to avoid plants drying out while they are hardening off is to transplant the seedlings from peat pots to 4 ½ inch or one gallon pots with regular potting soil. The plants really take off with the extra room and the larger pots are not as prone to drying out.

After two weeks or so, your hardy plants are ready to go into your garden.

For more information check out these publications from CSU Extension:

Plantalk 1034: Starting Seeds Indoors

Fact Sheet 7.409: Growing Plants from Seed

Fact Sheet 7.602: Saving Seed

Written by Mark Zammuto, a Denver County Master Gardener

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Is Your Xeriscape Ready for the Spotlight?

xeriscapeIf you think your water wise garden is ready for its close up, the Denver Botanic Gardens would like to hear from you. The DBG is looking for showcase gardens to feature on its Bonfils Stanton Water Wise Landscape Tour this spring.

Denver metro area gardeners who’ve taken their landscape water conservation efforts to the next level are encouraged to apply to be a tour garden. Selected gardens demonstrate the key principles of a water-wise landscape design.

To be considered, your xeriscape should feature a yard with either less traditional lawn or lawn alternatives, include native flowers and shrubs, have plantings of other drought-tolerant plants, and use water-conserving irrigation systems. It should also be beautiful, too.

The selected landscapes need to be in peak shape on Saturday, June 17, from 10:00 a.m. to 3:00 p.m.

If you have an anxiety attack at the thought of a few hundred people strolling through your backyard, this opportunity might not be for you. But if you’d like to help inspire others with your xeriscaping efforts, you might enjoy chatting with people throughout the day and answering questions about your experience, how the design saves water, how much maintenance is required, and the names of individual plants.

If you’re interested, apply sooner rather than later. “This is a rolling admission process so early submissions may improve the likelihood of selection,” says the DBG. For more information and to receive an application, send an email to Rachael Jaffe (rachael.jaffe@botanicgardens.org) or call 720-865-3613.

Getting Started with Xeriscaping

If your landscape isn’t tour-worthy – or you’ve been thinking about xeriscaping and don’t know where to start – now’s a good time start planning. Start by rethinking the ways you currently use water in your yard.

If that sounds overwhelming, start by transforming a small portion of your landscape. Small xeriscapes will still help conserve water. Look around your landscape and find the places where water use is the highest. Then find ways to reduce or limit irrigation, like seldom-used areas or parts of the yard that are highly maintained.

One of the best ways to save water in the landscape is by cutting back on turfgrass. How much irrigated lawn do you need and how much can be replaced with a lawn alternative? Just because you’ve always had a large lawn doesn’t mean you use it. Low-water grasses, ground covers, perennial flowers, and drought-tolerant shrubs can fill the space.

Another way to save is by rethinking ways to irrigate lawn areas separately from planting areas. Traditional systems can be replaced by low-pressure, low-angle sprinklers. In flower beds, use drip irrigation or soaker hoses under mulch.

Fill your xeriscape with colorful, climate-adapted plants that are known to grow well in our area, like the plants introduced through the Plant Select program. Group plants by their water needs, clustering together those that use less water in drier areas and those that need slightly more water in moister areas.

Mulch is also an important part of a xeriscape because it helps maintain soil moisture and reduce soil temperature. Depending on the plants you select, you may need rock, gravel, bark, wood chips or straw. Some xeric plants do better with inorganic mulches that let fast-falling rains percolate down to plant roots while reducing runoff.

CSU Extension has many excellent (and free) resources for getting started with xeriscaping. This fact sheet on transforming a conventional landscape to a xeriscape may lead to having your yard be part of a water wise garden tour in the future.

By Jodi Torpey
A Denver Master Gardener

It’s Winter and, Yet, I Dream of Cactuses

It’s January.  As I write, it’s cold.  It’s snowing.  The garden is frozen solid.  There isn’t much that can be done out in the garden.  But indoors, we can do a lot of thinking about and planning for about our gardens.  For me, this also includes thinking back to what has already been achieved. My special joy has been planning, making and planting my “desert garden”.

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Prickly pear peeks out of the snow

Having gained my gardening skills and horticultural knowledge in the temperate south of England, I was excited on moving to Colorado to try my hand at growing these interesting, drought tolerant plants.  Cactuses in England are generally small prickly jobs which sulk year-round in dry pots on the windowsill, gathering cobwebs.  I knew virtually nothing about them when I came to live in the USA.  My husband wasn’t much better; he told me he knew his cactuses had been over-watered when he saw mushrooms growing in their pots!

Call it what you will – rock garden, trough garden, crevice garden, desert garden. From big deserts to tiny tufa troughs, cactuses and succulents can be grown and enjoyed in many situations.  I know it’s the middle of winter right now, but I’m thinking of the sunny joy of seeing the Community Heroes Crevice Garden in Arvada and the new steppe gardens at Denver Botanic Gardens in the summer of 2016.  These showed me what could be achieved.  And as I gaze at the tips of Opuntia (prickly pear and cholla) plants poking through the snow in my front yard today, I am in awe at the extremes these amazing plants can tolerate.

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Opuntia x pinkavae

 

 

Our front yard faces north, not auspicious for cactus growing, but safely out of bounds to the dog and small grandchildren, and raised up above the sidewalk, so safely out of reach of passers-by.  The area I designated to be the “desert garden” is about 20 x 10 feet, bisected by the path from the sidewalk to the front door.  Despite its northerly aspect, this area does get a lot of sunshine from spring to fall.  A minimum of six to eight hours of direct sunlight daily is recommended for cactuses.  When we moved in, this part of the garden was just a boring flat patch of clay soil with rather elderly wood mulch strewn over it.  Again, not exactly the well-drained, lean (in terms of nutrients) soil usually associated with cactuses.  But I like a challenge!

To get things started, I raked off the wood mulch and underlying landscape fabric to reveal a flat, compacted, grey soil surface covered in the wriggling, white stems of bindweed like ghostly spaghetti.  I pulled as much of the bindweed as possible. Then to create some height and slopes I dug and shaped the soil into small hills sloping down towards the sidewalk.  We inherited hundreds of large granite boulders with the back yard, so my son and husband hauled a couple of dozen out to the front for me.  I chose the most attractive boulders and made sure they were of similar or complementary colors.  These were placed on the slopes, either singly as “specimen boulders” or in groups forming little “canyons” in which I could plant.

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Rocks, soil, river rock and neighbor’s turf

The slopes help to ensure rain (when we get it) runs off quickly so the plants don’t sit in puddles.  Pockets of water are trapped by the boulders giving little damp areas against the boulders and allowing water to slowly trickle down into the soil below.  To improve the soil drainage further, I dug in a couple of trailers’ worth of “squeegee” to a depth of approx. six to eight inches.  This is the name around here (I gather) for crushed gravel.  It is pinkish in tone and halfway between pea gravel and sand in size. Areas of small river rock (obtained for free from a neighboring garden which was being “re-done” – I love a freebie!) were laid as a transition from the “desert” to the greener area of the yard and the sidewalk.  After planting, a thick layer of pure squeegee was used as a mulch over the whole area.  This has been very effective at keeping the bindweed at bay, helped by merciless hand pulling of any little shoots that do make it to the surface.

The choosing of plants followed considerable book research, web browsing and advice from local nurserymen.  I used a mix of cactuses, succulents, grasses, small drought-tolerant perennials and bulbs.  Naturally, none of these are hot-house types.  They are all cold hardy down to at least Zone 4.  For many of them their natural environment is arid mountain-sides in Arizona and New Mexico where they bake in the summer and freeze in the winter. A couple of dwarf pines provide year-round green and structure.  (I had to remind myself that these two needed regular watering, unlike the rest of the desert garden, as they are young trees, albeit small.)

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Pinus mugo var. pumilio

Planting took place in June 2015, so these plants are now “enjoying” their second winter in our garden.  They spent two and a half months under snow in winter 2015/6 and came up smiling in spring 2016.  There were just two losses, both small Yuccas which had rotted at the crown.  Fortunately, I had extras safely potted up behind the house, so they were immediately replaced.

For the first summer, I watered maybe twice a week, using the mist spray on the hose head.  The second summer, 2016, I did not water at all.  The winter snow that laid on the area for two or three months or more, had provided a good reservoir of moisture which saw the garden right through the summer.

The immediate effect after planting was of a lot of very small plants stranded in a gravelly desert.  I believe in buying small and being patient for a year or two while the plants bulk up, seed around and acclimatise to their environment.

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Just planted, June 2015

 

And, now, after another summer, they are starting to do so.  I see little “pups” on the Echinocereus.  There are Sedum and Stachys seedlings. The stars are the Opuntias (tree chollas and prickly pears) and the Delospermas.  These have grown quickly and the Delospermas were carpets of jewel-like flowers for months on end.  Dianthus and Artemisias are soft foils to their prickly companions. Groups of Nasella tennuissima provide a feathery backdrop and transition to greener and moister plantings at the rear.  The gentle movement of these grasses is a nice contrast to the static cactuses. The little species tulips ‘Persian Pearl’ popped up beautiful purple-red blooms with yellow centers in spring.  I hope to see more of these this coming spring.

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Tulipa pulchella @Persian Pearl’

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Delosperma ‘Fire Spinner’

 

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Summer, 2016 (after the hail storm had knocked off all the flowers!)

 

Now it is getting established, it really doesn’t require a lot work.  No watering if we have enough snow in winter.  Minimal weeding.  A gentle blow-off of leaves and some careful extracting of same from the Opuntias’ prickles with the kitchen tongs once in the fall.  That’s it.

I love my desert garden and see passers-by enjoying it too and that just adds to the pleasure for me.

PS:  Cactus? Cacti? Cactuses?  Who knows … ?? Who cares … !!

Anne Hughes/a Denver County Master Gardener

https://communityheroesgarden.jimdo.com/

http://www.botanicgardens.org/

www.coloradocactus.org

Hardy Succulents: Tough Plants for Every Climate by Gwen Moore Kelaidis. Publisher: Storey Publishing.

Cacti and Succulents for Cold Climates by Leo J Chance. Publisher: Timber Press

Plant List

Cactuses

Echinocereus coccineus

Echinocereus triglochidiatus ‘White Sands’

Escobaria forcottei ‘Koenesii’

Agave utahensis var. kiahabensis

Tree cholla – Opuntia imbricata var. arborescens ‘White Tower’

Tree cholla – Opuntia arborescens var. viridifloa ‘Santa Fe’

Creeping cholla – Opuntia clavata

Prickly pear – Opuntia x pinkavae

Texas red yucca – Hesperaloe parviflora

Yucca flacida ‘Bright Edge’

Herbaceous perennials, bulbs and grass

Dusty miller/artemisia – Artemisia ‘Beth Chatto’ & Artemisia absinthium ‘Silver Frost’

Woolly thyme – Thymus pseudolanuginosus

Yarrow – Achillea sps. various

Sedum- Sedum spectabile various

Pinks- Dianthus sps. various + garden cuttings

Rock rose – Helianthemum sp.

Ice plants – Delosperma ‘Fire Spinner’ &  ?

Two row stonecrop – Sedum spurium ‘Tricolor’

Other stonecrops – ‘Vera Jameson’, ‘Lidakense’, ‘Angelina’

Mullein – Verbascum bombyciferum ‘Polar Summer’

Lambs ears – Stachys byzantinus

Feathergrass – Nassella tenuissima ‘Ponytails’

Species tulip – Tulipa pulchella ‘Persian Pearl’

Trees 

Dwarf mugo pine – Pinus mugo  var. pumilio

Dwarf mugo pine – Pinus mugo ‘Teeny’

A Year in the Life of an Amaryllis

amaryllis_akaIf your holiday amaryllis is nearing the end of its blooming cycle, here are tips to enjoy the plant through the year and give it the best chance to bloom again. Unlike paperwhites, which are one-and-done indoor bulbs, with care, amaryllis can re-bloom for years to come.

While flowering, the plant benefits from bright, indirect light and moisture. When each trumpet-shaped flower is finished, snip it off and when the last flower on the stem has shriveled, cut the entire stem about an inch above the bulb. Leave the strappy leaves in tact. Occasionally amaryllis won’t develop leaves until after blooming, so don’t fret if the plant is foliage-free at this stage. However, adding fertilizer to a bulb without leaves will kill the roots.

Treat the bulb as a houseplant throughout the winter by providing direct sunlight, watering when dry below the soil line and feeding common houseplant food once or twice a month. The bulb should remain snuggled in the original pot, with the top half to one-third above the soil line. In spring, the leaves will yellow and die, signaling that they’ve done their job of providing nutrients to the bulb, a common bulb process. Cut the foliage about an inch from the top of the bulb; new leaves will emerge through the summer. Leaves equal energy, so the more leaves developed at this time, the more vigor the bulb has to flower again. During the summer months, you’ll want to give the pot as bright a spot as possible, either indoors or out. Burying the pot in a partially shaded garden bed is also an option.

In September, reduce water significantly until leaves turn yellow and die. Store the plant in a cool, dark area (45 to 50 degrees) for 8-12 weeks, checking regularly for signs of new life and watering sparingly. This fall “Goldilocks” phase of not-too-hot, not-too-cold is critical to the forcing process so choose the resting spot carefully. When you see fresh growth, move the plant to bright light and resume regular watering. The plant is now ready to produce new foliage and flowers.

Many find this process a snap. If that’s not the case for you, keep in mind that the size and quality of the bulb can effect re-blooming, so from the start choose large, blemish-free bulbs which are heavy relative to their size. Amaryllis forced in water are also unlikely to re-bloom as they lack the energy to survive. But if this experiment doesn’t work for you, you may not want to give up as the bulb can take a year off from flowering and then come back with a vengeance. Growing amaryllis sure can be an exercise in patience!

Posted by Linda McDonnell, a Denver Master Gardener