Saturday, July 30, 2016

Serious Pest - Emerald Ash Borer

Please join me in your sympathy and concern for residents in Boulder County battling emerald ash borers (EAB). In the long term this serious pest won't remain in Boulder County. It's not a matter of "if" it is "when" they will reach other areas along the Front Range. 

Photo from City of Lenexa, KS
As serious pests, the harm they are causing to ash trees is devastating, but it is even more than that. Their presence leaves a sense of hopelessness and loss because there is no stopping it. Once infested, EAB can kill an untreated ash tree in 3-5 years. The emerald ash borer spreads easily from tree to tree - they can fly a half mile. They also spread by infested nursery stock, or firewood carried into uninfested areas. Boulder County has a quarantine on moving any ash wood out of quarantined areas.

Emerald ash borers are silent yet deadly to its host - all ash trees in the fraxinus genus. This includes the attractive autumn purple ash tree that causes driver double takes each autumn. It has been planted by many homeowners seeking and finding great satisfaction with brilliant fall red to purple leaf color. Finding replacement trees with equally fine fall color is possible, but it won't be easy saying good bye to these once easy-care trees. Emerald ash borers do not infest mountain ash trees which are in the sorbus genus. 

Emerald ash borer was first found in 2002 in southeastern Michigan and is now in 27 states plus parts of Ontario and Quebec Canada.  It was found in the City of Boulder in September of 2013.  It is considered the most destructive forest pest in North America, causing millions of ash tree death - those numbers will rise as the insect spreads to new areas, states and provinces. Follow the spread of EAB on this timeline.

Adult borers emerge from spring to summer to feed on leaves, mate and lay eggs in crevices and cracks of ash tree trunks. Eggs hatch in about two weeks, then the new larvae tunnel through the bark into the cambial region of the tree - this is the thin layer of cells just inside the trunk that grows wider each year.  The larvae feed on the sugars in the phloem (inner bark) of the tree, and long term the feeding causes the tree to weaken and eventually die. Adults are most active in the heat and sun from mid-day to early evening.  Males live for about a month, females up to two months and lay from 50 to 150 eggs during this time.

Tree damage is most noticeable on the main upper limbs and large branches.  Look for thinning in the crown of the tree and branches with yellow leaves. Sucker growth on limbs and trunks are indicators. Woodpecker activity is another sign of EAB presence, they peck and leave light colored patches of bark as they feed on larvae. The tell-tale D-shaped exit holes on ash trees are more visible proof of an EAB invasion. The outer sapwood of an infested tree (not visible from the outside) will reveal etched larvae galleries or s-shaped tunnels.

EAB infested trees Boulder, CO summer 2014

Tree industry professionals, City and State agencies and universities are doing all they can to educate the public on identifying ash trees, spotting the insect as an adult or damage left by the tunneling larvae. And most important in the education process are the spray or injection options for treating valuable ash trees and planting recommendations for replacing or adding new trees near ash trees. 


Read all about these options at Be a Smart Ash. Denver residents are eligible for free replacement trees in public right-a-ways, click here for more information - apply for a tree.  At only 1/2 inch long and 1/8th inch wide, Emerald ash borers have generated a tremendous amount of time, attention and dollars. 

D-Shaped Exit Hole
The City of Denver and surrounding counties have done an exceptional job in getting ready for the eventual arrival of EAB with monitoring and planning strategies. Click on any of the links below for additional information. 

Be a Smart Ash 

City of Denver Trees and Natural Resources 

Colorado Department of Agriculture 

City of Boulder 

Emerald Ash Borer Information Network 




Saturday, July 23, 2016

Relish or Hot Dog?

Ah... finally... the time of the season when gardeners and those who enjoy being outdoors relish in all things summer.  Enjoy it while it's here. Garden pleasure seekers relish in seeing terrific blooms, colors in shades or variegation of green, gray or blue.  And we love umphy plant structure. Nothing like a large clump of Black-eyed Susans or waving wands of lavender to grab your attention (and say to yourself - plant more of these).  Deep pink to red agastaches are calling hummingbirds to stop by for a sip while cucumbers lay in wait of a good plucking.  I'm showing my age (or desire to be a kid again), but there's still nothing quite like the taste of garden fresh cucumbers drizzled in ranch dressing.  Sorry foodies, but try it if you dare instead of the usual herb vinaigrette.

Leafcutter Bee on Seven-Son Flower
What do you relish about summer? The list may be long so get out outside and don't let the fast approaching August back-to-school season dampen your trips to local water parks, the mountains, the beach (this may require a plane ride) or a warm evening at Coors Field enjoying a cold drink.  Yea, the Rockies are once again under five hundred, but the people watching and views of the Denver skyline make it worth getting there.

I usually start each morning with a stroll around outside checking on what's blooming or soon to bloom and bending down for a closer look at the edible plants - they look pretty healthy so far this year.  Certain annoying insects must be flicked into a soapy jar of water, but I won't digress and spoil the "relish" mood.

Bumblebee on Coneflower
Nothing like breakfast on the patio and watching the dragonfly free air show over the grass.  Bumble bees seem plentiful this summer and so large I wonder how they keep afloat buzzing among the other expert flying pollinators.  Before I finish my cup of coffee and head inside to start the day a two-tailed swallowtail usually floats through the yard in search of a nectar snack or a nice leaf to lay an egg.  Thank you for stopping by to keep me company during breakfast.   

Summertime, garden time, relish time.  Might as well enjoy the hotdog too, don't hold the relish! 

Monday, July 11, 2016

Mid-Summer (third season) Vegetable Planting

The third season of vegetable planting begins soon. Check the chart for plants that can be seeded now and through August into early September.

There is plenty of time to seed many different crops that will mature in about sixty days. This is based on a mid-October hard freeze.

Tuck in the seeds wherever there is room. Later in August and September you can seed lettuce, spinach, arugula and radishes-the quicker maturing cool-season crops. 

Cool-season vegetables and herbs that can be seeded right now include beets, Brussels sprouts, cabbage, cauliflower, cilantro, Swiss chard, collards, bunching onions, parsley, peas.

Warm-season vegetables and herbs that can be seeded right now include basil, bush beans, slicing cucumber, okra, New Zealand spinach, summer squash.

Fall or Third Season Planting Calendar for the Colorado Front Range
Use of cold frames or tunnels may help extend the season

CROP –
COOL
SEASON
DAYS
TO
MATURITY
FALL SEED
Based on
Mid-Oct. Freeze
Arugula
30
Mid-August
Asparagus
Perennial
Early Spring Plant
Beets
60-65
Mid-July
Broccoli
70
Mid/End-July
Brussels Sprouts
80-95
Mid-July
Cabbage
60-70
Mid-July
Carrots
55-75
End July
Cauliflower
50-55
Mid-July
Cilantro
55-65
Mid-July
Chard-Swiss
50
Mid-July
Celery
85-110
Spring Plant
Chinese (Napa) Cabbage
48-55
End July
Chives Onion
Perennial
Spring-Fall Plant
Chives Garlic
Perennial
Spring-Fall Plant
Collards
50-55
Mid-July
Garlic

Mid-Sept
Mid-Oct
Horseradish
Perennial
Spring-Fall Plant
Kale, Mustard Greens
50-55
Early August
Kohlrabi
55
Mid-
August
Lettuce Leaf
40-45
Mid-August
Lettuce Head
70-80
Early August
Onion Bulb
100
Spring Plant
Onion Bunching
60-80
Mid-July
Parsley
75
Mid-July
Parsnips
85-120

Peas – shell and snap
50-65
Mid-July
Peas Edible Podded-snow
60
Mid-July
Potato Tubers
80-120
Spring Plant
“New” Potatoes
50-60 days
Spring Plant
Radishes
20-30
Early Sept.
Rhubarb
Perennial
Spring-Fall Plant
Rutabaga
90-95
Early August
Shallots
110
Early Sept. Zone 5 or warmer
Spinach
30-50
Mid-August
Turnip
40-75
End July
CROP –
WARM
SEASON
DAYS
TO
MATURITY
FALL
SEED
Based on Mid-Oct. Freeze
Basil
60-85
Mid-July
Beans, Bush
45-50
Mid-July
Beans, Pole
60-65
June-July
Corn, Sweet
65-80
Spring Plant
Cucumber
Slicing
48-72
Mid-July
Cucumber
Pickling
48-58
Mid-July
Eggplant
60-80
Spring Plant
Cantaloupe
85-120
Spring Plant
Okra
55-65
Mid-July
New Zealand
Spinach
50-60
Mid-July
Pepper
70-80
Spring Plant
Pumpkin
95-110
Spring Plant
Squash
Summer
55-65
Mid-July
Squash
Winter
55-105
Spring Plant
Tomato
60-85
Spring Plant
Tomatillos
75-100
Spring Plant
Watermelon
75-100
Spring Plant