How to Grow Asparagus

asparagus planting in Woodland Hills, California, more than 30 years old, harvest season just ended

asparagus planting in Woodland Hills, California, more than 30 years old, harvest season just ended

Question: Three years ago we planted about 10 asparagus roots (crowns).
They grew and we didn’t pick any asparagus sprouts (shoots). After they died back, I cut them back. The second year they came up and we picked some sprouts. I may have cut them back before they completely died back.
We were anticipating a grand harvest this year, but we got nothing. A few spindly sprouts came up, a few edible sprouts and a number of seedlings. That’s all.
Did I cut them back too soon? What do I do next?
– Russell Patterson
Santa Clarita
Answer: Whenever I receive a question about problems growing a vegetable or fruit crop, I always ask first about light exposure. Unless vegetables and fruit trees receive all-day sun, producing a crop may be problematic.
So I asked Russell about his exposure and learned that there is a mulberry tree that blocks some of the sun’s rays during the summer.
Without full sun asparagus will not photosynthesize at maximum capacity, which means that foliage will make less food to be sent down to rhizomes for storage for the following year’s spears or shoots.
During the first half of the 20th century, there were commercial asparagus farms from Van Nuys to Newhall, proof positive that our area is highly suitable for growing asparagus. The advantage of growing asparagus, as opposed to other crops, is that plants are perennial and will produce for up to 25 years, with good crops expected for 15.
With asparagus, preparation is the key to success.
Dig trenches 8 to 10 inches deep and plant asparagus crowns or seedlings in well-composted soil at the bottom of the trenches. If you plant crowns (seedling bases and their one-year old root systems), firm soil around the roots and cover crowns with soil but do not fill the trench.
As the plants develop, backfill trenches with more enriched soil, leaving growing tips exposed. By the end of the season, plants should be growing above ground level and trenches should be filled to the top.
Where soil drainage is poor, plant in raised beds.
Normally, crowns are planted in the fall. The first spring, refrain from harvest and wait until summer or fall, when growth has turned completely brown before cutting to the ground.
The second spring, harvest for four to six weeks, and the third spring harvest for up to 10 weeks.
Harvest asparagus spears, which should be cut at an angle so as not to injure adjacent spears, below ground level. Refrain from harvesting spears whose diameter is less than that of a pencil.
Asparagus is dioecious, in the manner of date palm, pistachio and carob trees, meaning that it has separate male and female plants.
Female plants are less robust since they produce seeds, sapping their strength so that, over time, an asparagus planting will consist largely of male plants.
There are also hybrid varieties, however, such as ‘Jersey Giant,’ that consist entirely of male plants.
Asparagus requires its fair share of water and fertilizer. Prior to planting – and each spring prior to emergence of new growth – you can apply 1 1/2 pounds of 10-10-10 fertilizer per 100 square feet of growing area.
Russell, in your particular case, I would prune your mulberry tree to make sure your asparagus receives at least eight hours of sun each day.
Asparagus soil should also be kept moist but not wet. However, better to err on the dry side since asparagus plants will rot in soggy soil.
Q: In my backyard, I have an eastern redbud (Cercis canadensis) ‘Forest Pansy.’ For the last 14 years this beautiful tree has performed exceedingly well.
However, this spring it started out with its pink blossoms as usual but then the rains came and the wind. Now the pink blossoms have faded and darkened and no leaves have appeared. I cut a branch off and saw no dead wood but the tree looks dead.
Does this spell the end of my redbud or do I wait until next year to see if it blooms again?
Is it possible that the high winds and heavy rain has anything to do with the tree’s present condition? Can a tree go a whole year without leaves and still survive to reproduce the following year?
If all else fails I will wait until next year to see if it buds. The tree is a
main fixture in my patio and a
great source of shade.
– Mike Uetz
Burbank
A: Eastern redbuds are short-lived trees due to an apparently ubiquitous canker disease, instigated by an airborne fungus, which causes dieback of stems and branches.
In their habitat, encompassing the entire Southeastern United States as well as much of the Midwest, eastern redbuds rarely reach 30 years old. Those that do reach this age benefit from near constant moisture in the root zone.
Of course, constant moisture around the roots of any plant can be a problem of its own because of other soil-borne, moisture-dependent fungal pathogens, which may also kill eastern redbud trees.
In any case, it stands to reason that a tree native to a marine climate, with precipitation expected in every season, would be stressed in our climate with its long, hot and dry summers. It may well be that ‘Forest Pansy’ has a life span of about 15 years in Los Angeles.
I would be interested in hearing from anyone who has a ‘Forest Pansy’ tree that is older than yours.
For the last several years, ever since they were planted, I have been admiring a stand of ‘Forest Pansy’ trees on an embankment just below the Burbank Boulevard offramp of the southbound San Diego Freeway. I have noticed that one tree is already struggling and not nearly as robust as the others. I will be noting the progress and longevity of these trees to see how long they endure life in the mid-Valley.
The wind and rain would not affect your tree’s health and I doubt that your tree will leaf out next year if it does not do so now.
In the vast majority of cases, trees of small stature are short-lived. This is certainly true of ornamental peaches, plums (e.g., purple leaf plum) and pears, which are unlikely to live more than 20 or 25 years. Acacia trees are short-lived as are silk trees (Albizzia julibrissin).
Crape myrtles may live for 50 years but their attractiveness declines considerably after 20.
One small tree I would recommend is weeping bottlebrush (Callistemon viminalis). I have one that is more than 50 years old, is drought tolerant, and flowers on and off through the year, displaying vivid scarlet bottlebrushes that attract hummingbirds. It also gives excellent shade at its mature height of around 25 feet.
Q: I read your column on brambles, but I didn’t see any caution about their spreading root systems, which can take over a yard.
For several years I had boysenberries. They were delicious, but pruning and cleanup took a lot of work every year. Finally, I couldn’t put up with the lawn infestation and they had to go. Their roots extended 40 feet into the lawn, putting up shoots all over the place. After taking them out, including the root ball, I spent the next five years digging out the remaining roots and the shoots that kept on popping up in the lawn.
I think your readers might appreciate a recommendation to put a barrier around the brambles.
– Nick Kurek
Granada Hills
A: I appreciate your pointing out a possible pitfall of planting brambles.
Many kinds of root barriers, from various textile fabrics to modular plastic panels, are available through Internet vendors, as a search for “root barriers” will amply demonstrate.
Be aware that use of plastic root barriers, often used in parkway strips to inhibit root growth of trees, is an inexact science. I have seen several cases where plastic barriers stunted tree growth to the point where barrier removal was necessary to keep the trees alive.
Tip of the week
I was recently stopped in my tracks by three wonderful ground covers for semi-shady Valley exposures. Dalmatian bellflower (Campanula poscharskyana) comes at you in foamy waves of lavender blue and is the perfect companion to purple shamrock (Oxalis regnellii triangularis), an edible perennial with deep purplish maroon, triangular leaves and pale violet-pink flowers. Erodium ‘Bishop’s Form,’ a member of the geranium family, is an excellent selection for rock gardens and fast-draining, granitic soil.

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