CO-Horts Blog

Monday, June 30, 2014

Planting that Birthday Tree

Kurt M. Jones
Chaffee County
Extension Director

Sitting here on my back porch, looking past the potted rosemary and basil, I can see my son’s birthday tree in the back corner.  Grandpa and Grandma bought us a birthday tree in celebration of our son’s first birthday.  With an extension agent son-in-law, I’d better have planted it correctly!
Planting a tree correctly actually starts with tree selection.  We purchased a Colorado Blue Spruce for a couple of reasons.  First was because of our son’s being enamored with our tree during the holidays last December.  Second, this tree fit into our landscape plans well.  Finally, it is one of Dad’s favorites.
After looking at the available trees in the nursery, I chose one that had a couple of features that I was interested in.  First, I was looking for a tree that had good shape, and more importantly, one “leader” branch that was vertical.  I was also looking at the root ball for two items: ease of handling without a tractor, and the presence of stabilizing roots in the top 2 inches of the rooting soil.  Roots that are deeper in the ball or potted tree have the danger of being planted too deeply, lessening the chances of establishment or long-term survivability.  The tree that I chose was one that was potted (rather than ball-and-burlap) so that I could move it through our fence with a furniture moving hand cart.  Larger B&B tree stock often requires specialized equipment to move due to the weight and rounded shape.  One drawback of potted trees can be the lack of root ball as compared with the size of the tree, so extra care may be needed to establish a potted tree as compared with B&B trees of similar height.
After getting the tree home, it is time to locate it and dig the hole.  We chose a location that will allow for mature size of the tree.  It is also relatively level, and it is in a location that we can regularly irrigate year-round.  Many of the tree problems that I have seen this year can be attributed to our dry fall and early winter, necessitating year-round irrigation once the tree is established and during tree establishment.
The hole that I dug was saucer-shaped.  I dug it 2 inches shallower than the height of the tree ball, and the edges were 3 times the diameter of the root ball.  Yes, a big hole.  Tree roots will grow primarily in the top 12 inches of soil (rather than developing “tap roots”) and spread laterally from the base of the tree.  The depth is dependent upon the available moisture and oxygen levels in the soil; too shallow and there is inadequate moisture, too deep and oxygen levels diminish. 
Why the saucer shape?  Researchers have found that in some cases, tree roots can turn upon themselves when faced with a vertical soil texture change (like those faced with the conventional tree holes with vertical sides taught years ago).  Saucer-shaped holes lessen the likelihood of tree roots turning on themselves, eventually girdling the tree as they mature.  Digging the hole larger has been shown to increase root biomass eight times over similar trees with holes dug to fit the root ball.
After digging the hole, I removed the plastic container and the burlap that was also present.  Though burlap will eventually degrade, I did not want it wicking moisture away from the tree roots or interfering with root establishment until it degraded.  My preference is to remove as much foreign material (wire cages, burlap, strings, pots) as possible when planting trees.
When I got the tree upright in the hole, I began backfilling.  I did not use any amended soil in my backfill, instead I planted the tree in an amended location.  Tree roots spread laterally from the base, so amendment is best accomplished throughout the rooting zone, not just in the backfilled hole.  I also water-packed the backfilled hole, rather than tamping or stomping in the soil around the tree roots.  My purpose in digging a large hole was to avoid soil compaction, so I will avoid activities that contribute to soil compaction around the tree.
Finally, I drove some wooden stakes through the root ball into the undisturbed soil underneath to help stabilize the tree during periods of higher winds.  Because this is a special tree to our family, I wanted to use underground stabilization rather than straps, wire and T-posts to hold it in place.  If you choose to do wrapping around the tree to stabilize it, make sure you use straps designed for that purpose, and remove the stabilization materials after the tree is established (approximately 1 year later).  I had the unfortunate opportunity to see some established trees planted about 8 years ago that succumbed to the girdling effects of tree wraps (lengths of garden hose with wire inside).  I also mulched the entire area of disturbed soil to help hold moisture and reduce weed establishment.
Though I did not use any, many people believe that root stimulation hormones should be used.  Though research is conflicted about using root stimulator, it does not harm the tree and may help with speeding up root establishment.  One practice that should not be used is nitrogen-based fertilization.  The goal after transplanting trees is to establish tree roots rather than producing tree branch growth.  Nitrogen fertilization during the first growing season has been shown to reduce root growth.  Finally, I watered the tree ball and surrounding soil.
             The simple act of planting a tree.  It is a practice that has many opinions, but for our family, planting a “First Birthday Tree” is a neat tradition that I was proud to be a part of. 

Wednesday, June 25, 2014

Pueblo's Annual Xeriscape Tour

Posted by Linda McMulkin, CSU Extension-Pueblo County

A fun and educational event happened recently in Pueblo and Pueblo West.  Ten gardens were open to the public, with name tags on plants and information about design and maintenance in the garden biographies and plant lists, and homeowners and experienced gardeners onhand to answer questions.  Why, I can hear you thinking, did you miss the Xeriscape Garden Tours of Pueblo and Pueblo West? 
This garden is surrounded by lawns, making this unique front yard
a reason to slow down for a look on a busy Pueblo street.

The xeritour is a collaborative event, planned and supported by CSU Extension-Pueblo County, the Southeast Colorado Water Conservancy District (SECWCD), and the Pueblo West Community Xeriscape Gardeners. Gardens are chosen based on beauty, but must conform to water-wise gardening principles. The goal is to provide inspiration and to demonstrate that even in the harsh conditions of Pueblo and Pueblo West, homeowners can have sustainable, colorful landscapes that are long on beauty but short on water bills and maintenance. 
After fighting to keep a lawn healthy on a steep slope,
the homeowner  terraced  the front yard and created a
show stopping water-wise landscape.

This large garden is designed to feed the bees! 

This was the 9th year for the tour, which is held the first weekend of June and attracts about 200 people to each garden.  Gardens in Pueblo are open on Saturday and the event is organized by SECWCD staff and Colorado Master Gardener volunteers.  The 2014 event featured the public gardens at the Sangre de Cristo Art Center and 4 private gardens in older neighborhoods that had been remodeled from turf  to colorful, waterwise landscapes surrounded by mature trees.  

Sometimes it's not about the plants,
but about  the fun.  The homeowner saw
 this idea online and decided to give
the courtyard vegetable
garden some extra color.
On Sunday, the tour featured gardens in Pueblo West, showcasing young landscapes that support native arthropods, provide water for birds, and include edibles for the homeowners.  The public garden at Cattail Crossing looked the best it has in years, showing that when nature provides some spring rainfall, a low-water garden can truly shine.  This garden was awarded the Plant Select Showcase Garden Award last June and is managed by the all-volunteer Pueblo West Community Xeriscape Gardeners.
Why not add a putting green in your patch of turf?
Especially if you can make it look this good.
The foreground shows the bare soil that
most Pueblo West gardeners start with.  The
homeowner is a Colorado Master Gardener
and a member of the Pueblo West Community
Xeriscape Gardeners.


At Cattail Crossing, a large turtle was spotted  laying eggs among
the perennials.  Pea gravel must make a nice nesting site.
On the left, the same garden from the human view. 
The garden is open year round, near the intersection
of McCulloch and Joe Martinez in Pueblo West.
All photos by CSU Extension-
Pueblo County staff. 

Mark your calendars for the 2015 Xeriscape Garden Tour in Pueblo on June 6 and Pueblo West on June 7.  The tour is free and maps will be available on the CSU Extension website in May next year. 

When Herbicide Goes Bad

Posted by: Tony Koski, Extension turfgrass specialist

Who would have ever guessed that the turf specialist would start looking up and noticing all these trees in our landscapes? What a strange world. But the more I look, the more fascinating those tall leafy plants become. And one thing I’ve noticed this year is an onslaught of herbicide injury occurring. Recently I’ve been on several site visits and a common theme seems to be chemical injury.  (Don’t worry…we still have all those other problems like drought stress, planting depth and chlorosis.)

So this seems like a good time to remind people to be careful about using herbicides near any plants, as they can be damaging and even lethal to woody plants. First of all, apply all pesticides (this includes fungicides, herbicides and insecticides) according to the label. Use proper application equipment, mix at the recommended rate and wear appropriate protective clothing and eyewear. Some chemicals have limitations of how warm it can be when spraying (chemicals have the potential to volatize and turn into gases). Don’t spray on windy days…the lightest breeze can cause chemicals to travel great distances. It’s best to spray early in the morning when it’s still cool outside.
Possible 2,4-D and dicamba injury on redbud.
Herbicides, in particular, tend to affect plant tissue as growth regulators or amino acid inhibitors. Growth regulators (usually from selective herbicides, like Weed-B-Gon or 2,4-D) can cause leaf cupping, coiling and bending. Leaves can also be misshapen. These herbicides may suppress growth, cause iron chlorosis, blacken tissues and cause defoliation.
Misshapen aspen leaves from possible 2,4-D injury.
Amino acid inhibiting herbicides (from non-selective chemicals like Roundup) can cause strap-like leaves, bushy growth, misshapen leaves and injury may be delayed into the next growing season or longer. This can occur when glyphosate is sprayed on suckers at the base of trees; green, exposed roots on the soil surface; and green bark at the base of trees or on the trunk. 
Glyphosate injury on ash.
Depending on the dose of what was sprayed on/near the tree, herbicides can cause long-lasting damage—and may even kill the tree. Remember the herbicide doesn’t know the difference between a weed in your lawn and your beautiful, blooming linden. But you do. Be careful out there.
An ash severely damaged by glyphosate.

Thursday, June 19, 2014

Lessons Learned from a PhD Defense

Posted by: Alison O'Connor, horticulture agent, Larimer County Extension

Today was the defense of my PhD dissertation. I'm happy to report that I passed. (YEAH! CELEBRATE!) But it was also a lip-biting, stressful and smack-your-forehead-in-stupidity event. Let's set the tone. There was me. And five highly educated, accomplished and smarter-than-whips professors...all with their PhDs. All who've been in your seat. All who want to kinda-sorta make you squirm like they did on their defense day. That in itself should make you break into a cold sweat. Which I did. For 2.5 hours.

The Professors ask you questions. A lot of questions. Questions that you SHOULD know on any regular day, but don't when you're being grilled. Questions like, "Alison, what is another possible cause of "air root pruning" besides air?" Or "What soil has the greatest total porosity? Clay or sand?" "Can you explain what the difference is between potential and actual evapotranspiration?" No, I can't. Google, where are you when I need you???

So what did I learn from today? And what does this have to do with a horticulture blog? Well, let's see if I can tie the two together...

I learned that I need to learn more. Just like gardening. We learn every year. We learn from each other. And when you think you can't learn any more than you already know, there's someone who can silence your smarts with a simple question ("Why is water important to a plant?").

I learned that the professors I admire (and respect) most are my allies. They want to see you succeed. Squirm, yes. But ultimately succeed. They want you to grow and flourish. Let's just call them "fertilizer for the mind."

I learned that being considered the expert can be uncomfortable. Theoretically, I knew my research better than anyone in the room, but when the questions started coming, I realized I might not be the expert I thought I was. And that's ok. There is always more to learn and that's why the field of science is so fun to work in.

I learned that my extensive knowledge of the Beatles and rock music history was not helpful in my defense.

Finally, I learned that doing any degree takes a lot of perseverance, sacrifice and dedication. There are times I wanted to give up, much like when your garden is hailed out and everything is smushed to smithereens. There are ups (getting published!) and downs (losing data). But ultimately, the journey is worth it. Biting into your first juicy tomato of the season is the gardener's reward. My reward is receiving an 8.5"x11" piece of paper with my name on it, followed by the letters "PhD." Both rewards are equally awesome (though some would argue the tomato is more tasty...and useful).

And actually, the Beatles did come in handy. Because I couldn't have done this without "A little help from my friends." Thanks to all who've helped me, supported me and cheered me on. I promise to blog about my research soon, since we found some really incredible things. Stay tuned!

Monday, June 16, 2014

Posted by Mary Small, Jefferson County Plant Diagnostic Clinic

The Attack of the Flea Beetles
Apple flea beetles on apple
 Our extension research and demonstration garden on the Jefferson County fairgrounds is home to many vegetable and fruit projects, including some espaliered apples.
While checking on spring growth, my colleague and I were horrified to find an enormous crop of shiny apple flea beetles dining, mating and crawling on the leaves. We’ve found them before in the adjacent garden on evening primrose, but have never seen them on the apples.  Interestingly, they are only on the espaliered ones!
In an historic journal from Kansas State Agricultural College (now Kansas State University), the apple flea beetle was noted in orchard trees “in the lower branches only and near the ground." Our affected tree branches are closer to the ground than branches on the nearby upright trees. Maybe there’s something to what the early Kansas researchers reported.  
Flea beetle damage on tomato
Over in the tomato planting, potato/tomato flea beetles are feasting on the plants destined to be a seed source for our seed library project. Although the size of the infestation wasn’t quite as alarming as the apple one, we need these tomatoes to make it past young plant-hood! Volunteer Master Gardeners have been out vacuuming off the little beasts and applying diatomaceous earth. 
I’ve read that 50 or more holes per leaf are needed before there is any adverse effect on plant growth, but really hope they’re gone before getting that far. If management tactics aren’t deemed to be at least moderately successful, we may have to pull out some bigger guns.  But time will tell. 

Friday, June 13, 2014

Mid-June Gardening Chores

Posted by: Jim Klett, Professor and Extension Horticulture Specialist

When should I prune my overgrown forsythia in my garden?

Along the Front Range, we generally enjoyed a good early spring for forsythia bloom due to many of the newer clones such as ‘Meadowlark’, ‘New Hampshire Gold’, ‘Sunrise’, and ‘Northern Sun’, which have better flower bud hardiness and are being sold and planted more. One should prune forsythia after flowering by thinning one third of the older canes by cutting them to ground. It is important to remove the oldest branches and weak and dead wood. This will encourage new growth and more flower buds which are formed in late summer to fall for next spring.

If the shrubs are overgrown, you may want to rejuvenate your shrub in February by trimming the entire plant to 3 to 6 inches above the ground.

No matter which of these two pruning techniques you choose, your overgrown shrub will bloom heavier and will be more showy in future years. You will lose bloom color if you choose rejuvenation  pruning but will gain it back in future years.
[photo by David Staats]
Forsythia in full bloom at the CSU Arboretum

My irises are done blooming and is this the time to divide?

Clumps of bearded irises should be divided and replanted before they become overcrowded. A single rhizome will branch many times over the years, developing into heavy criss-cross clump, often choked with old leafless rhizomes. If it is not divided, the mass of leaves will exclude sun and air from roots. This will lead to poor flowering or no flowering and often weakens the plants making them more susceptible to insects and disease.
Photo by David Staats

Dividing of irises is best done after bloom (late June into July) which is the same time that plantings should be made. Lift each clump by gently prying it loose from the soil. A spading fork is better for this than a shovel because it is less likely to cut roots and rhizomes.

Use a sharp, strong bladed knife to trim younger rhizomes into sections that include healthy looking roots and one or two strong leaf fans. Carefully wash soil off roots under low pressure from a hose. Discard old rhizomes from center sections.

Trim existing leaves to a neat fan shape and then dig a hole to replant so that the rhizome will be set no deeper than one inch. Check to be sure that all leaf fans face the same way and spread roots out evenly. Firm the soil around the rhizome to eliminate major air pockets in the soil. 

Photo by David Staats

Monday, June 9, 2014

I'm the Queen of the Garden!

Posted by: Darrin Parmenter, Director and Horticulturist in La Plata County

Down here in SW Colorado, we are just getting around to putting tomatoes (and other warm-season crops) in the ground. As our days get warmer, here are a couple of things you can do that will have your tomato plants thanking you. And perhaps you can make the diva happy, because really, that’s what gardening is all about.

·                     Deep thoughts. If you haven’t put your transplants in the ground yet, remember that they appreciate being planted deeper than they were in the container. Leave 3-4 branches above ground and remember to pinch off all flowers and fruit. Your plants, and BLT sandwich, will thank you later.

·                     Turbo boost! Up until the first fruits are 2 inches in diameter, feed the plants a water soluble fertilizer every two to three weeks. Organic alternatives would be fish meal or powder, and blood meal or bat guano, both of which need to be applied carefully so you don’t burn your plants.

·                     Put ‘em up! Tomato cages or concrete mesh work well for indeterminate plants with multiple stems; stakes are preferred for plants that have 1 to 3 stems. Be careful with twine – it may cut into the stem. Plant-tape or cloth works best for tying. Think about tying your stakes to each other (horizontally) for added support.

·                     Stupid side suckers. These form in the crotches or axils of the plant and act as a sink for vital nutrients and carbohydrates. So pinch or prune them off. If suckers appear below the first fruit cluster they may compromise the strength of the plant. As the plant grows, pruning becomes more of a challenge – so focus on the suckers that are still succulent and can be pinched-off easily.  

·                     More please... Give the plants healthy drinks of water regularly and deeply while they are rapidly developing. Plants need roughly 3-5 gallons of water each week.  Infrequent and irregular water can lead to blossom-end rot.

Taking tomato planting to a whole new level O_O
This is how we grow them down here in Durango! Photo courtesy of here.

Monday, June 2, 2014

Leave Those Leaves!

By Micaela Truslove
Broomfield County Extension

There is nothing more delightful than early-blooming spring bulbs pushing through the snow; the first sign that spring has arrived. What is less delightful is when the flowers begin to fade, the leaves discolor and flop, and you are left with a clump of sickly looking foliage that is begging to be ripped out and tossed into the compost pile.

But wait! As tempting as it is to tidy things up by chopping off the yellowing foliage, these spring beauties need those fading leaves to feed the bulb for next year's blooms. When the foliage is removed too soon, bulbs may fail to bloom next spring. Tying or braiding the foliage may make things look a little more orderly, but it also reduces the amount of leaf area that is exposed to sunlight, which can interfere with photosynthesis and food storage (and it sounds horribly tedious).
As unattractive as the fading leaves of these tulips are, 
remember to leave those leaves to ensure you'll have 
gorgeous blooms next year.

Do remove the flowers as they fade. This will keep things looking neat longer and helps to conserve the bulb's energy by redirecting that energy back into the bulb and not into seed production. This will also prevent the more unruly bulbs, such as Muscari, from running rampant throughout the garden.

If the weather is warm and dry and the leaves are still going strong, continue to water. It may take four to six weeks before the foliage dies back and is ready to remove. Once this happens, remove it by gently pulling it from the ground (it should come away easily), or trim with scissors.

If you enjoy having spring flowering bulbs, but don't want to look at the unsightly foliage once they are past their prime, consider planting them among perennials that will leaf out in time to disguise the senescing leaves. Try mixing bulbs with coral bells (Heuchera spp.). These come in an ever-growing assortment of colors. Alison's last post has some great suggestions. Bearded iris (Iris germanica) is a great accompaniment to taller bulbs, such as daffodils. Others to try are Oriental poppy (Papaver orientale), Hosta and daylily (Hemerocallis).