Thursday, March 12, 2009

Fruit trees on the Front Range

The biggest challenge with growing fruit trees on the Front Range is winter and spring “roller-coaster” temperatures. Fruit trees must tick off chill units to complete winter rest. Each variety has unique number of chill units. Warm temperatures above 55 degrees F will subtract from accumulated chill units delaying spring growth. Sound like this past winter? Once the rest requirement is satisfied, chill units are ignored until fall when they are reset by the next winter dormancy.

Following rest satisfaction, plants begin accumulating heat units for growth until full bloom. Again, each variety has a unique number of heat units (called growing degree hours or days). If this number of heat units is small and the tree is in full bloom when temperatures drop, blossoms freeze and the fruit crop is lost.

Finding fruit trees “programmed” with the right chill units and heat units for the Front Range is hard due to the unpredictability of our winter and spring temperatures (the “roller coaster”). While some trees may fruit one year, the crop is lost the next. With many types of fruit, realizing a crop one or two years out of five is typical. This is why there is no substantial commercial fruit industry here and instead it is found on the West Slope where temperatures are moderated.

What are the most reliable fruit tree varieties for the Front Range? Of course some that will grow here have other problems such as how susceptible apple and pear varieties are to fireblight disease. This is the time for readers to step up and tell us their experience.
What type of tree fruit do you grow (apple, peach, cherry, plum etc.), what is the variety, what is your crop record (estimated number of crops in the last 5 years), and tell us your Front Range city?

Click comment below and let us know.


[Bowl of apples photo credit Carl Wilson]

12 comments:

  1. Hi all, we are sad to have lost our apricot blooms this week from a very, very old central Denver tree after last years abundant crop--first one in 14 years.
    Blooms at the end of the branches--anyone have guesses as to old varietal that it might be??

    ReplyDelete
  2. We have 2 apple trees. I have no idea as to the variety, they were here when we bought this house. They have over the last 7 years had a crop every other year. We get an abundance of small apples with lots of worm damage. We're due again this year for more apples.

    ReplyDelete
  3. I forgot to add that we're in Arvada.

    ReplyDelete
  4. Hi Carl. I've marked your site and plan to visit often. Front Range gardening baffles me! We've been living in Wetmore (6600 ft) for 10 years now and tomato growing is a challenge. I haven't even tried fruit trees - the crab tree usually freezes out. But - wonders of wonders - there is an amazing old apple tree next to Hardscrabble Creek that produces tons of worm free apples (without any help that I'm aware of) most years (except last year - we're not sure if people or bears got to it first). I want that tree! I'm checking your blog for tomato help. I love tomatoes and I can't grow one that half compares to Michigan tomatoes. I think it has someting to do with hot days and too cool nights. What do you think of portable greenhouses? I wonder if they'll blow into the next county but really want the day time heat to stay in.

    ReplyDelete
  5. Suzan lives at higher elevation outside the approximately mile high elevation Front Range cities that are the main focus of this blog.

    F.R. gardeners have better if variable success with growing warm season vegetables such as tomatoes than high elevation gardeners where root and leafy vegetables are better bets. At high elevation the only recourse is experimenting with a handful of extremely short season, small fruited tomato types - or better yet growing in a coldframe or best in a greenhouse.

    On the other hand, in more consistently colder winter areas at higher elevations the fruit trees developed for the upper Midwest can be grown (see http://www.colostate.edu/programs/wcrc/pubs/research_outreach/treefruitcoldclimate.pdf). Finding fruit tree varieties that are geared to surviving and bearing well under the roller coaster F.R. winter temperatures is a whole different challenge.

    ReplyDelete
  6. Our neighbor last year had beautiful bountiful sweet peach harvest on her tree 2 summers ago, but last year only yielded 5 on the same tree.
    We have planted a dolgo apple from Fort Collins Nursery - heard they drop a lot and can be messy, but sounded like a good trial, and last summer the fruits were very small and sour... those were the first fruits and first summer here in Fort Collins.

    ReplyDelete
  7. About apples. I have a 35 year old tree in the backyard which is
    either a winesap or macintosh. It does produce large quantities about every other year. We are in Lakewood.

    The tree was professionally pruned last year, and this year we are
    expecting the bounty crop which will produce enough to keep us in dried apples, sauce, and frozen pie fillings for 2 years! The apples are wormy as I do not spray due to the extreme size of the tree.

    ReplyDelete
  8. Has anyone had success with plums? I am in Colorado Springs (we're consistently cooler and our climate is even more unstable than Denver.) I am deciding whether to plant a plum or a pear or just skip them both and stick to berry bushes. If I do go with the trees, I plan on planting a sour cherry along with whichever (plum or pear) tree has a better track record. I've lived in this town for 15 years and I know our challenges, but a gardener's hope springs eternal! Thanks!

    ReplyDelete
  9. Heather,
    I'm in Fort Collins (and think we're more unpredictable than Denver area as well). Don't know of many pears in town, but recommend Mount Royal plums which are among the hardiest plums and produced a bumper crop this year (2009).

    ReplyDelete
  10. Hi,
    I am in Applewood (in Lakewood) and there are tons of appletrees around here. I talked to one of our neighbour that has about 20 apple trees and he said when his father lived here, the area was a huge apple orchad. Anyway, to get back to the topic, in fall 2008, there were apples everywhere around here. Tons on the ground, and that neighbour was giving away apples by the bucket. You would see apples/crabapples all over the street. Fast forward to fall 2009, no apples in sight. I sure hope we'll have some in fall 2010.
    We also planted 2 plum trees. The first year (fall 2008) we got 3 plums. The second nothing but as there were no apples either, i assume we got the same issue with the flowers (i think we got a huge snow storm when the trees flowered)

    ReplyDelete
  11. We've had two apple trees in our back yard for about ten years; a Haralson and a Jonathan. In the last few years they only have about five to ten apples on each one in the spring and drop off before they mature. We have tried fertilizing each spring and water them regularly throughout the year. When we planted them we amended the soil which is clay. Any suggestions?

    ReplyDelete
  12. My Honeycrisp has had a good crop every year for past 5 or 6 years, every year since it was mature enough to bear apples. It is planted in an unprotected location and has little summer irrigation in Boulder County.

    ReplyDelete