Welcome To The Blog That Gives You The Plant Grower's Perspective!

Preparing The Nursery For Winter

Posted by Paul VanOteghem

Preparing the nursery for winter

Home nursery container production farmWinter preparation at Home Nursery is not a one-time event, but rather a year long process.  With container production, many of the activities and decisions of the year must be completed with a forward-looking thought of winter.  There is nothing more disheartening than to produce a beautiful crop through the growing season only to lose it or have it damaged during the winter.  Much can be done to protect crops from winter damage through careful planning throughout the year.

Over the past several years, we have been blessed with relatively mild winters.  The danger with this is becoming complacent and lulled into a false sense of security when it comes to winter preparedness.  The following are issues that must be dealt with at Home Nursery to ensure successful over-wintering, regardless of its severity.  

  1. Crop rotations are planned so that varieties requiring similar over-wintering techniques are grouped together.  At Home Nursery, all of our container plant material spends the winter under poly in the typical quonset style cold frame, but species that we have learned to be exceptionally susceptible to winter damage, such as Ilex, Berberis, Cotoneaster, etc., will receive an additional covering of poly.  This double covering is achieved in one of two ways.  We have some poly houses set up with smaller bows within the larger bows of the house over which another covering of poly is pulled when low temperatures dictate.  Other houses simply have poly blankets that are pulled directly over the crop as needed.

  2. Fertilizer choices throughout the year are made with a thought of winter.  At Home Nursery, we incorporate controlled release fertilizer (CRF) in our media at the time of canning.  For us, there is rarely a month of the year where we aren’t canning something.  Our goal is to have this incorporated source of fertilizer depleted by November.  Thus we make our choice of fertilizer longevity by backing up from this November date, starting with  8-9 month fertilizers early in the year and switching to 5-6 month, then  3-4 month and finally ending with a product that will provide nutrition for just a 1-2 month period.  For us this provides easier management of our fertility levels the coming year with everything starting out at the same point at the end of the growing season.  Beginning in February, nearly all carryover crops will receive a top-dressing of another CRF with a release longevity of 12-14 months.

  3. Poly orders are placed for the coming winter just as the poly is coming down in the spring.  This allows poly suppliers to deliver on time.  With much of the poly being produced overseas, early ordering is critical.

  4. Most of our new poly house construction is completed during late summer and early fall.  At Home Nursery we bend our own bows, so the tubing for this, generally ordered in truckload quantities, must be ordered well in advance, as the steel mills can take four to six weeks to deliver the material.

  5. Irrigation water can be applied more sparingly beginning in September with the advent of cooler weather and shorter day length.  This will hasten dormancy.

  6. September brings an end to the growing season.  Inventory and quality control personnel get very busy in September as they start the final grading and counting process.  This is where the men are separated from the boys.  In other words those plants that have reached a saleable size and quality for early spring sales are differentiated from those that still need a little work.  We attempt to trim as much as possible of this latter group prior to the covering of the houses.  This practice has proven to be a large labor saver for us as trimming is much easier while the plants are still fully spaced on the growing range, and clean-up of the trimmings is much more efficient.  Typically time runs out far before this trimming is completed, as we must start the process of setting the plants together under the poly house bow.  Those plants that did not receive their pruning will during December, January and February.  It should be stated that caution must be exercised if one decides to do this late fall trimming…it must be done late enough in the season that a pruning will not initiate new growth.  If new growth were initiated, it would most likely be damaged in the fast approaching cold weather.

  7. “Set-together” or “jamming” is the next step in winter preparation.  This is the process whereby we move plant material that has spent the growing season spaced out on their growing ranges to their winter homes under the bows of the poly houses.  We start in early October with smaller, younger crops and progress to larger plants later in the month.  As with most things, different approaches must be taken with different crops.  Deciduous shrubs and perennials can be placed pot to pot for the winter, as can smaller sized conifers and broadleaved evergreens. We place our larger conifers and broadleaved evergreens to bed for winter in a configuration we call semi-spaced.  Here the plants are far enough apart that there can be some air movement and sunlight can reach lower branches.  Our goal is to complete the jamming process by early November.

  8. Field grown Taxus are harvested during the month of October forB&B Taxus winter storage in the poly houses.  We typically harvest approximately 12,000 units, which enable us to get a jump on the early spring shipments.  This also assures that in the event of a severe, open winter without snow cover, that we would have some product protected from the possible damage that can occur in the field.

  9. Several years back we experienced a combination snow/rain/ice event which we were unable to keep up with. The weight became so great on some of the houses that they snowloadpolyhouse collapsesnow propsstarted collapsing.  In total we lost nearly 1.5 linear miles of polyhouse.  I resolved that this would never happen again on my watch.  So now part of our yearly routine is to install what we call snow props in each house prior to covering.  Pictured here is a 2x4 placed vertically under the purlin every 25 foot.  They have not been fully tested with a similar storm, but I feel confident they will buy us some time and save some heartache.

  10. Jamming is wrapping up as the covering process begins.  With approximately 20 linear miles of poly houses on the Albers farm to be covered, a daunting task awaits the nursery crew.  Our goal is to have the majority of the houses covered by Thanksgiving.  We will start with liner houses in the propagation range, as they are most susceptible to early damage because of their small root mass and polyhouse coveringcontainer size.  Covering of varieties for which dormancy comes late, such as Spirea, Roses, and Hydrangea, will be put off to near the end.  Some of our hardiest varieties such as Junipers and Arborvitae may not be covered until the first week of December depending on weather.  It is frequently not until the end of December or even into January that we close the doors on the houses. Throughout the winter we closely watch conditions and attempt to keep temperatures warm enough to avoid damage, but cold enough (through ventilation), to maintain dormancy.

  11. Farm fields surround our growing operation in Albers, Illinois.  By late October, most of the row crops have been harvested and the varmints that spend their summers in the fields are now beginning to migrate, and are looking for new homes and food sources for the winter.  It is typically at this point that we start to bait for rodents such as voles and to make sure that all rabbit barriers are in place on doorways into the poly houses.  Vigilance when it comes to these pests is necessary throughout the winter as they are capable of causing serious crop damage. 

Once everything is put to bed for winter we can complete any unfinished trimming, apply the top-dressing of fertilizer, and do some winter canning and propagation.  During those cold winter days of January and February, thoughts of spring will set in… when the poly comes down… and the cycle begins again.

Tags: Local, General, Winter