Category Archives: Summer gardening

Celebrate the Unsung Insect Heroes During Pollinator Week

It’s Pollinator Week 2018, a time to show some garden love to the bees, butterflies and other insect pollinators that provide services essential to our food supply.

This year, let’s put the emphasis on other insect pollinators.

It’s easy to admire beautiful butterflies sailing effortlessly from flower to flower. We all know how important it is to provide nectar and pollen for native bees. But how many gardeners really, truly appreciate flies? How about other non-bee insects, like moths, wasps and beetles?

These less lovable insects are what some researchers refer to as the “unsung heroes of the pollination world.”

Bees certainly get the most notice for their important work, but they couldn’t do all the pollinating on their own. They need help from other less attractive insects.

In a revealing research study, one Washington State University doctoral student discovered that flies are an important pollinator, too. During her research, Rachel Olsson found that about a third of the insects visiting farm crops were syrphid flies, also known as hover flies.

These flies mimic the behavior of bees, help with pollination and do a bit more. In their juvenile stage, syrphid flies help control aphids, too.

Rachel’s research was funded by a grant from the Western Sustainable Agriculture Research and Education program. She spent several years studying whether non-bee insects contribute to sustainable crop pollination on a network of 24 organic farms in Western Washington.

During her study, she learned pollinators were drawn to one type of crop over another. She had hoped to observe bee and non-bee insects interacting in a way that could improve pollination efficiency.

Still, these overlooked pollinators provide a valuable service and need to be part of conservation efforts, too. That’s why Rachel thinks the results of her research are applicable to Colorado gardeners. It’s important to understand and protect all pollinators, especially the underdogs of the insect world.

An especially useful guide is a booklet Rachel co-authored called, A Citizen Guide to Wild Bees and Floral Visitors in Western Washington. Published by Washington State University Extension, the online guide provides tools for observing and identifying wild bees and other important floral visitors.

By Jodi Torpey
A Denver Master Gardener

Advertisements

Japanese Beetles Make Their 2018 Debut

 

jb_1

The Japanese Beetle – pretty to look at but oh so destructive!

June is a glorious month in the garden, but it also the cue for adult Japanese beetles (Popillia japonica) to emerge from the soil. They’ll hit their peak from late June through at least August. I haven’t spotted the metallic green and copper devils in my garden yet, but if the past is any indication, they’ll visit soon.

Colorado State University offers this comprehensive fact sheet with everything we need to know to defend our plants. It’s an especially valuable reference when considering products which may or may not be beneficial in reducing the pests while doing minimal damage to the ecosystem. If there were best seller lists for gardener information, this would be on the top!

Here are important takeaways from the fact sheet:

05601-fig5Japanese beetles feast on foliage, buds and flowers of their favorite plants. Particularly susceptible are roses, Virginia creeper, Linden trees, Rose of Sharon, Japanese maples, Silver lace vine and Gaura are among their favorite targets. Tell-tale signs of Japanese beetle damage are a skeletonized pattern of mutilation on tender, new foliage and deformed flowers or buds. While unsightly, the damage will not kill the plant.

05601-fig8Traps are not beneficial. That yellow trap you’re tempted to hang in your yard is an open invitation for more Japanese beetles to visit. The trap won’t be able to catch them all and the effect is more, not less damage. Perhaps if your neighbor hangs one…?

Picking does help. Japanese beetles are easy to spot in the cooler parts of the day and can be coaxed into a jar of soapy water with a twig or a shake. Catching is preferable to squishing, as a squashed beetle releases a compound which lures more of their kind. While it may not be fun, catching is oddly satisfying!

Do insecticides work? As always, caution must be used to avoid damage to pollinators, especially when plants are in flower. Products containing pyrethrins, azadirachtin and acetamiprid – used in the early morning or at dusk – when bees and other pollinators are less active – are the safest. See the fact sheet for more details and follow all product recommendations carefully.

Consider removing temptation. Can you replace your Virginia creeper with something less enticing? Do you have roses that have struggled for years? Perhaps it’s time to replace with something less alluring. Conversely, when adding to your landscape avoid plants which are irresistible to this insect.

Late season turf damage. Each female Japanese beetle lays 40-60 eggs in her 4-8 week life span. Eggs are laid deep in moist turf soil. Since eggs and subsequent larvae thrive on moisture, keeping soil on the dry side will inhibit grub development and decrease turf damage. Grubs also munch on turf roots, so mowing at a higher height, which promotes vigorous roots, can help reduce turf damage.  More control ideas can be found in this fact sheet.

Have you spotted Japanese beetles in your garden yet?

 

Submitted by Linda McDonnell, a Denver County Master Gardener

 

Gallery

2018 Plant Sale Shined Despite Bad Weather

This gallery contains 7 photos.

Stormy weather failed to dampen the spirits of gardeners at the 13th annual Denver Master Gardener plant sale.  In spite of cloudy skies and cool temperatures, the cash registers recorded around 4000 transactions! “We definitely had our best sale ever,” … Continue reading

Slow Food Helps Grow Kids

An important part of the children’s garden was helping kids connect to nature by learning about the colors and magic of fruit. Other beds were filled with all the plants needed to make salsa, a nutrient scavenger hunt and salad greens as an equation for success.

There was a lot to love about the Slow Food Nations festival in downtown Denver over the weekend.

The celebration of local, organic and sustainable foods included free food tastings offered by Slow Food groups from around the world, educational programming and vendors selling to the thousands of foodies that attended the event.

But one of my favorite displays was the children’s garden, located on the sidewalk just north of the Taste Marketplace.

In this series of raised bed gardens, kids had the chance to get their hands dirty by exploring gardens filled with fruits, vegetables, herbs, grains, and flowers.

One of the premier gardens included a sample of the modular Learning Gardens, created by The Kitchen Community. The Kitchen Community’s mission is “Community through Food” and it accomplishes that goal by building outdoor classrooms on school playgrounds around the country, including Denver and Fort Collins. There are more than 400 to date.

The customizable gardens are designed to fit into each school’s landscape and become part of the educational process. As a teaching tool, the gardens help students learn about growing and eating nutritious foods and gaining healthy habits to hopefully last a lifetime.

A bowl of dried corn and a grinder were placed next to a bed of corn plants. Kids were encouraged to try their hand at turning corn into a grain for cooking.

 

 

 

 

 

 

 

 

 

The Low Tunnel garden bed introduced kids to the the concept of helping plants grow before and after summer. Books on year-round gardening surrounded the bed as resources for kids and their parents.

 

 

In addition to all the herbs, fruits, and vegetables, there were beds of flowers to promote planting for pollinators. A sensory garden helped kids see, smell and feel the benefits of plants.

 

 

 

 

 

 

 

 

 

By Jodi Torpey
A Denver Master Gardener

Never Put a $10 Plant in a 10¢ Hole and Other Gardening Tips From Denver Master Gardeners

planting-1898946_1920Passionate gardeners love to talk about gardening, so with that in mind, we recently asked Denver Master Gardeners for their best gardening advice. Responses included tried-and-true practices, creative suggestions and good reminders for all of us as the gardening season kicks into full gear.

As the title of this post implies, we believe that great plants come from appropriate soil preparation. Amending with compost is often imperative as soil in our region tends to lack organic matter. But proceed with caution, as some plants, such as natives, prefer a leaner, less fertile soil. Too rich soil will cause these plants to underperform and often just flop over. It pays to do a little homework before planting, read seed package directions and have your soil tested.

One of our gardeners shared her recipe for amending soil: Add 1/2 a handful of both Alaskan fish pellets and triple super phosphate to half a bucket (such as a kitty litter pail) full of compost. Mix this into the planting hole for strong root development and beautiful blossoms.

A tip borrowed from the Rock Garden Society is to plant bare root. By gently shaking off most or all of the soil that the plant is purchased in, the plant will adjust to the garden soil without the soil interface (or boundary) that can occur between two soil types. Bare root planting promotes healthy root development.

mulch-1100555_1920Mulch, mulch, mulch is the mantra of many of our survey respondents as it keeps weeds out and moisture in. Add it like crazy each time you dig in the veggie, perennial and annual gardens and don’t forget container plants too. Small to medium-sized bark chips are popular, practical and pleasing to the eye. Natural mulch options are very effective, including not quite finished compost from the compost bin which will add carbon, feed living organisms, prevent water runoff and prevent compaction. Local arborists are often willing to drop off wood chips which would otherwise fill up the landfill. In the fall, mow over your leaves and spread them throughout the yard, they’ll breakdown by spring and add organic matter to your soil. Consider purchasing a chipper to grind up branches and other garden waste.

garden-hose-413684_1920Suggestions for responsible use of water include watering when the plant needs it instead of on a set schedule. Soaker hoses, often made from recycled material, are effective for watering plants at the soil line. Plants (even xeric ones)  need moisture to maintain healthy roots and overall strength, but often less than we think. For example, the Water Smart Garden at the Denver Botanic Gardens is watered about seven times during the season.

Weeding can feel like a no-win battle, but attacking weeds after a soaking rain makes the task easier. Pull weeds and unwanted volunteer shrub and tree seedlings when they are small, before they take hold in the ground or develop seed. Add stepping stones to the garden to avoid stomping on plants and compacting soil when working in the garden.

bindweed-1207738_1920A clever tip to eliminate stubborn weeds, such as the nasty bindweed shown here, is to take a large piece of heavy cardboard, make a cut from the edge to the center. Keep the cardboard as level as possible, slip the vine in the center and spray the vine with the herbicide of your choice or horticultural vinegar, which is sold in garden centers. The cardboard will protect surrounding plants from overspray. Aggressive weeds may require multiple treatments during the season.

One of our members recommends a tomato planting technique passed on through generations of farmers. She adds blackened banana peel to the soil and feeds them with skim milk upon planting and again one month after that. This less conventional practice yields her sweet, abundant fruit. While CSU can’t vouch for the scientific efficacy of this, the banana could be adding potassium and the addition of calcium may reduce the chances of blossom end rot.

plant-1585251_1920Growing tomatoes in containers is recommended for those with limited space. Select varieties which produce smaller fruit such as Patio, Cherry or Sungold. Use a large container (18+ inches in diameter), a sturdy support and a tray with casters. This allows plants to be moved from the path of hail or to optimal conditions. Container plants of all kinds benefit from weekly feeding of 1/2 strength fertilizer.

To keep pests at bay, try a thorough weekly spray of water during the growing season, including the walls of the house and fence. It’s a kinder way to shoo pests away.

If your vines need a sturdier trellis consider building one out of remesh, which can be found at hardware stores. It makes a durable, cost-effective support and can easily be cut with bolt cutters. It also can be attached to supports to create a dog run or create plant cages.

botanical-garden-413489_1920In the flower garden, invest in perennials for texture and dimension and add annuals for bold color. “Enjoy the randomness of some plants that choose their own spots to thrive” suggests one gardener. What a positive way to think of the seedlings that sprout up at this time of the year. Remember, too, that perennials may not come into their glory until the second growing season.

Gardening is a four season hobby. Winter watering of trees and shrubs will help keep them healthy and  veggie gardeners can get a jump on the season by using a cold frame or floating row cover to get an early start on lettuce, spinach and other cool season crops. Fall is a fantastic time to fertilize, aerate and over-seed the lawn. It is also an ideal season to divide perennials so that they settle in and are ready to take off in the spring.  Share your divisions with your neighbors, too, or trade for plants you’ve admired (envied?) in their yards. If you need more gardening space, solarizing or sheet composting is an excellent technique to ready a new garden bed and can be started throughout the year.

And lastly, a veteran gardener advises us to “Remember each little garden flower or planting arrangement is a moment in time. It will change. Don’t worry about it or take it too seriously.”

 

Written by Linda McDonnell with thanks to the many Denver Master Gardeners who shared their advice.

All photos courtesy of http://www.pixabay.com, a source of royalty free images.

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

4 Ways to Share the Harvest

Share the HarvestOn August 8 I saw a picture on social media of three oversized zucchini squashes lined up against someone’s front door.

Apparently it was National Sneak Some Zucchini On Your Neighbor’s Porch Day and gardeners were making the most of it to get rid of their giant zucchinis.

I know summer squashes can be the punch line to gardening jokes, but I didn’t know there was a whole day devoted to surprising neighbors with jumbo fruits that might go to waste.

Good gardeners know that zucchinis are best when they’re small and tender. To avoid club-sized fruits, harvest early and often, when fruits are about 5-7 inches long. It pays to remember at the height of the season, fruits can be ready to pick within a week of flowering.

Instead of unloading zucchinis onto unsuspecting neighbors, why not donate the extra produce to people who will appreciate it? Here are four ways to share the harvest with a food pantry that will distribute it to our neighbors in need:

AmpleHarvest.org
Ample Harvest is a national charitable organization that connects gardeners with local food pantries by zip code. On the website homepage there’s a Find a Pantry button at the top of the page. When I keyed in my zip code, I found a dozen pantries within a 9-mile radius.

Colorado Hunger Free Hotline
In addition to being a food resource, the Colorado Hunger Free Hotline can help gardeners find a food pantry that accepts fresh produce. Call 855-855-4626 (Monday-Friday, 8:00 a.m. to 4:30 p.m.) and ask about food pantries located in your zip code. Then get in touch with the pantry for details about dropping off your fresh fruits and vegetables.

Fresh Food Connect
Fresh Food Connect is a local project of Groundwork Denver, Denver Food Rescue and Denver Urban Gardens. The program has three goals: reduce food waste, collect fresh produce and employ low-income youth. Fruits and vegetables are collected from your front porch and either donated or sold at a youth farm stand. If you live in zip code 80205, you can sign up and get a weekly email asking if you have any produce to donate. Someone on a bike with a trailer will ride by and pick it up.

Fresh Food Connect organizers say the program will expand to other neighborhoods, so even if you don’t live in the 80205 neighborhood, sign up so they’ll have an idea of where to expand the program in the future.

Project Angel Heart
Project Angel Heart takes fresh fruits, vegetables and herbs and turns them into healthful meals for their clients with life-threatening illnesses. Project Angel Heart has a list of accepted items, especially chard, tomatoes, zucchini! and yellow squash (see the full list and other details on the website).

Produce must be harvested and dropped off on the same day: Mondays, from 8:00 a.m. to 3:00 p.m., at the Denver office and kitchen (4950 Washington St.).

If you have a favorite drop-off spot, please add it to this list and help other gardeners find the best use for their extra produce. And let’s start celebrating zucchinis for their important role they play in our gardens — and kitchens.

By Jodi Torpey
A Denver Master Gardener

Help, My Garden is Wilting!

Have you ever noticed your perfectly healthy plants wilting at the end of a hot, sunny day? This is the plant’s way of protecting itself from the elements, much like our bodies adjust to temperature changes. Plants routinely gather moisture and nutrients from the soil through their roots and move it up transpirationtheir stems and leaves. Moisture is then emitted back into the air through pores on the underside of the leaves, called stomata. This process is called transpiration. On an especially hot day, the leaves will begin to emit more moisture than the roots can supply, which triggers the pores to close. As a result, the leaves lose rigidity and wilt but the plant is protected from further loss of moisture. While all plants transpire, broadleaf plants such as cucumbers, squash, hydrangea and many annual flowers are especially susceptible to heat wilt.

To  help your plants recover:

  • If the soil is moist about an inch under the soil line, the plant will likely recover on its own in the cooler night air. If it is dry, water the plant at the soil line and check in the morning; again, the plant should have perked up.  If the coming day will be another scorcher, consider a bit more morning water to avoid further late day stress.
  • Be gentle around the limp foliage, it is stressed and can easily break.

To reduce the potential for heat wilt:

  • Add 2″-3″ mulch around  plants, stopping at the outer edge of the plant so water can be absorbed easily.
  • Promote healthy roots by routinely watering deeper a few times a week versus a daily short spritz.
  • When adding new plants, loosen soil deeply and add organics such as compost to aid in drainage and root development.
  • Consider location when planting. Afternoon sun is very likely to wilt plants that need only partial sun. Also pair plants needing the same water and light conditions together.
  • Add succulents and plants requiring less water to your garden. They will thrive during the dog days of summer.

Transpiration fun facts and resources:

  • An acre of corn can transpire 3,000-4,000 gallons of water a day.
  • Transpiration is to thank  for the comforting shade under large trees. Eighty percent of the cooling effect of a shade tree comes from the evaporative effects of transpiration.
  • Much more on the transpiration process can be found on CMG Garden Notes 141 and at http://water.usgs.gov/edu/watercycletranspiration.html

 

Written by Linda McDonnell, a Denver County Master Gardener

 

 

 

 

 

 

Four Ways to Celebrate National Pollinator Week

Today’s the official start of summer and it coincides with another important annual event — National Pollinator Week. From June 20 through June 28, agencies, organizations, companies and ordinary gardeners bring attention to ways to help build healthy environments for bees, butterflies, birds, bats and other vital pollinators.

Here are four ways to celebrate pollinators this week. Please add your ideas to the list:

Million Pollinator Garden Challenge1. Register your garden on the National Pollinator Garden Network.

Become one in a million by registering your pollinator-friendly garden as part of the Million Pollinator Garden Challenge. The goal of the challenge is to register 1,000,000 public and private gardens and landscapes that give pollinators what they need: nesting sites and plants that provide pollen and nectar.

Pollinator Friendly Jacket Image2. Learn more about pollinators.

There are many free pollinator guides available if you need help deciding which plants give the biggest bang for pollinators. There’s also a new book written by a gardener for gardeners. Pollinator Friendly Gardening by Rhonda Fleming Hayes explains that no matter the size of your garden, there are dozens of good plants for helping pollinators. Her detailed plant lists simplify selecting flowers, herbs, vines, shrubs and trees.

3. Become a Habitat Hero.

Encourage more feathered friends to gather in your landscape through the Habitat Heroes program with Audubon Rockies. Apply to have your landscape recognized as a Habitat Hero wildscape. Some of the basics include planting bird-friendly native and regionally-adapted plants, reducing herbicide and pesticide use, and controlling invasive plants.

Pollinator Bee4. Plant zinnias.

A single packet of zinnia seeds will give you a summer full of color and plenty of lovely nectar-filled landing pads for bees and butterflies. Zinnias are some of the easiest annual flowers to grow whether in garden beds or containers on the patio, balcony or deck.

Please keep pollinators in mind and let’s work together to create a lot of buzz during National Pollinator Week!

By Jodi Torpey
A Denver master gardener

 

Hail Season is Here – Don’t Despair!

Gardening along the Front Range of Colorado is not for the faint of heart. We have to deal with poor soil, wild temperature swings, intense sun, a short growing season and hail. Somewhere in the Denver Metro area someone will experience the heartbreak of hail this season. It is hit or miss from year to year, but it is inevitable. The results can be devastating. In a few minutes,  a gardener’s hard work can lay in ruin.

Hail June 2015

Hail – June 2015

The first thing to remember when you experience hail damage is not to panic or lose hope. That is hard to do when everything in your garden has been shredded to confetti.  The initial inclination is to give up for the year and pull everything out. Don’t do it. Take a deep breath and stand back. Some plants may be done for the year, but others will come back even if they look terrible right now. Plants want to grow. They have an amazing ability to come back.

In 2015, our garden experienced two severe hail storms: one at the beginning of June and one the last week of June. We knew that most of our perennials would come back with time, but our vegetables were in a sorry state. Most were reduced to green sticks with a few tattered leaves hanging on for dear life. At that moment, it was hard not to throw in the towel for the season and head to the farmers market for produce. After much wailing and hand wringing, we went out in the garden and cleaned up the dead plant material. We took care to leave any foliage that looked like it might have a bit of life left.  Then we waited. Within a week or so, our tattered vegetable plants showed signs of renewed growth. Soon they were leafing out with abandon. We helped them along with light applications of liquid kelp fertilizer. By the end of July, we were harvesting vegetables from the same plants we thought were lost in June.  It was not our best harvest, but it was very good given the challenges we faced.

One small confession – we did buy a few new plants to hedge our bets. It was late in the season to buy vegetables at the garden center. The selection was not great.  The replacement plants got a late start and needed to get established. In the end, the replacements did not do as well as the original plants. Although the foliage on the original plants was shredded, those plants had been in the ground for over a month and had strong established root systems.  It’s not always what you see above ground that matters most.

If you have the misfortune this season to be hit by hail, remember:

 

  • Don’t panic.
  • Clean up the dead foliage.
  • Leave foliage that still has life.
  • Do light applications of fertilizer.
  • Be patient.
  • Click here for more tips.

By Mark Zammuto,  Denver County Master Gardener