In Praise of Willow Trees

Am really excited about our Willow Tree Production and about the increasing role willows are playing in Shelterbelt programming.

Our Current Crop of Willow is a big one with over 300,000 container root willow.  We focused on producing the hardiest fast growing varieties: Golden Willow, Shrub Cluster Willow and Pussy Willow (with minority amounts of Laurel Willow and Silver Leaf Willow also produced) 
Some of the Things that Make Willows Great

1) Why I like the Golden Willow 
The golden willow has a low and very wide canopy. Even by the end of the first growing season the golden seedling can have both the leader and as many as ten branches all in excess of one meter of growth if they have adequate rainfall or irrigation.  This compares to the hybrid poplar that can have similar fast growth but the poplar will have just a single leader with that height.  So you can see the wind stopping potential of the golden which can eventually have a spread of 30 feet in a typical shelterbelt compared to the poplar with a fraction of that spread.  The more dense the branches the greater the perocity fence effect the trees will provide. 

The hybrid poplars were developed as a more drought resistant alternative to willow that required more moisture.  However, there are a few tricks that can help the greater wind stopping willow establish on sites with less abundant moisture. Rule one: Plant them deep! 
90% of what makes a tree seedling establish or not is all about having sufficient water. By planting willow seven to nine inches of depth ...meaning the five inch root plus another two to three inches of stem buried below the ground surface, this helps ensure two things.  It helps ensure the root is well sealed and not aerating to the surface. Secondly deep planting helps ensure the willow roots are closer to or within the more semi permanent sub-soil clay moisture. This makes the willow far less reliant on surface rainfall or irrigation. 

In my experience the fastest growing willows we have at HELP are the Golden, the Pussy Willow, and the Cluster Shrub Willow.  The golden willow was also the most hardy in field plantings.   

Other Willows I like: 
Pussy Willow:  Our field planted pussy willow were the most desired food source for deer.  Even throughout the high rainfall summer we had and the bio-diverse fields of alfalfa, brohm, fescue and slough grasses and forbes along with cereal and oil seed crops on neighboring properties the deer selected the pussy willow to heavily browse throughout the summer but did not touch the goldens, the silver leaf and only occasionally browsed the Laurel leaf willow.   The heavy browsing did not negatively affect the pussy willow.  Its true the deer kept the pussy willow shorter but the plant's branches, made shorter from browsing became thicker and more hardy than the other willows. 

Laurel Willow: Though seeming to require more water than the golden to keep up in growth rate to the golden I like the Laurel for several reasons: I love the green rubbery texture of the leaves.  The laurel is also in my opinion the woody willow that is the most resilient against frost and high winds.  In fact it holds onto its leaves far into the end of November this year, more than a month after the other willow and poplar varieties lost their leaves.   

Spreading Bamboo Shrub Willow
I like this willow due to its erosion control capability.  It spreads in all directions and many folks like the bamboo shoot appearance of it. That is, it grows with hundreds of single straight leaders two to three meters high and six to twelve inches apart across the landscape.   This willow can establish and spread on both low lying creek margins as well as on the top of higher drier river escarpments that might only see water once per year during the spring run off period.   I like a tree that multiplies itself without human efforts.   

Silverleaf Willow:  This willow is said to be more drought resistant and slower growing.  I did find it to be far more slower growing than the other willows but I really did not find it more drought resistant.  I found the Golden to have an equally high establishment rate in our non irrigated but plastic mulch film regime in HELP fields. 

Where I would Plant WIllows: 
I would plant willow not only around sloughs and on stream margins but also on any level terrain.  If you plant the willow deep the willow can establish with far greater success.

Where I would not Plant Willow
I would not plant willow next to ditches or valley escarpments nor on the tops of rolling lands which have poor sub-soil moisture retention.  Poplars are still the fast growing tree of choice for these type of drought prone landscapes.  For the most severe drought prone sites the green ash is the most drought resistant (and interestingly the most flood resistant) woody species tree we have on the prairies. 

Summary: Willows can be established in a far wider range of landscapes than traditionally thought if you:
i) plant them very deep to access more semi-permanent sub-soil moisture
ii) employ plastic mulch film or other mulch
iii) or if you regularly cultivate as an alternative to mulch application
iv) if you are in a position to water the willow three or four times per year especially on  their first year  of planting. 
v) If you want to promote bio-diversity the pussy willow is a preferred food source of deer.
   (the pussy willow HELP produces is the one with the spongy leaves with a texture not dissimilar to the spongy velosa lilac leaf in appearance and feel) 

Sizes of Willow at HELP: We are very pleased with the willow sizes we have produced. Our goldens  and cluster shrub willow average about 20 inch stems.  Our pussy willow are about 16 to 20 inches.  Our other willow varieties are mostly in the 12 inch range.