January 2020 - 30

VARIETY INFORMATION
Approximate Grow Times for 1-Gallon Containers
When Spring Planting 3-Inch Liners
Shrub
Abelia
Aronia
Berberis
Betula
Callicarpa
Calycanthus
Caryopteris
Cephalanthus
Chamaecyparis
Clethra
Coprosma
Cornus
Cotinus
Cotoneaster
Cytisus
Deutzia
Diervilla
Euonymus
Exochorda
Forsythia
Fothergilla
Genista
Heptacodium
Hibiscus syriacus
Hydrangea
arborescens
Hydrangea
paniculata
Hydrangea serrata
Hydrangea
syriacus
Grow Time
in Weeks
11
11
16
11
9
11
9
11
9
13
14
13 to 15
11
13
11
11
9
13 to 15
13
11
14
13
11
13
9
12 to 14
9
12 to 15
The actual grow times will depend on the species and cultivars being
grown the actual size of the starting materials used and the production
temperatures they are grown at.
Although some of the shrubs listed above may bloom, the grow times
shown are generally the time it takes to produce a marketable plant.
30 JANUARY 2020 GPNMAG.COM
Shrub
Hypericum
Ilex
Juniperus
Lagerstroemia
Ligustrum
Lonicera
Loropetalum
Lycium
Parthenocissus
Philadelphus
Physocarpus
Potentila
Prunus
Rhamnus
Rhododendron
Rosa
Salix
Sambucus
Schizophragma
Spiraea
Symphoricarpos
Syringa
Taxus
Thuja plicata
Viburnum
Vitex
Weigela
Grow Time
in Weeks
13
13 to 15
13
9
11
13
14 to 16
9
11
15
13
11
13
13
13 to 16
10 to 12
12
9
13
9
9
13 to 15
16
11 to 13
11 to 15
11
9 to 12
When considering which sized starting material is best, be sure to
consider the number of grow weeks required before assuming a larger
sized input is more costly. In many instances, larger inputs can be grown
significantly faster and actually cost less to produce than when using
smaller inputs, which require more production time and plant maintenance.
This should go without saying, but use larger-sized starting materials
for finishing large containers. An alternate strategy can be to plant
multiple smaller-sized liners into large container sizes. The choice to
use small starting materials or the wrong number of inputs will require
more production time, extra trims, decreased final plant quality and
less profitability.
Plant vigor and production temperatures are the other considerations
that greatly influences how much time a crop takes to grow. Several
suppliers of starting materials have this information and make it available
in their catalogs, on their websites or they will be happy to assist you with
selecting shrubs that fit your production system and sales goals.
Contrary to the idea that shrubs are long-term crops, many of them can
be grown in surprisingly little time. Take Hydrangea serrata, for example;
it has a vigorous growth habit and can be grown in as little as nine
weeks when 3-inch liners are planted into 1-gallon containers. Shrubs
with average growth rates and vigor will take slightly longer and require
approximately 12 weeks of production time. Numerous shrubs have a
slow growth rate and will take at least 18 weeks of grow time to produce a
finished one gallon container.
CULTURAL REQUIREMENTS
Besides being woody ornamentals, shrubs aren't altogether different to
produce than perennials. In fact, their cultural practices are fairly similar.
Contrary to the idea
that shrubs are long-term
crops, many of them can
be grown in surprisingly
little time.
QUICK CROPPING SHRUBS
When determining how much time to allow in the spring, the main
considerations are the vigor or growth rate of the shrub, the size of
the starting materials, the final container size and the production
temperatures. When growing shrubs, consider each crop individually as
one production protocol for every shrub will likely not be suitable for all of
the varieties being produced.
There is a wide range of liner sizes available to use as starting
materials. Since most shrubs are vegetatively propagated, it's rare to find
starting materials smaller than 72-cell sized liners. Liner sizes commonly
available range from 2-inch to 4 ½-inch liners or pots (40-cell cell trays
to one-quart sized containers). It's also common to upgrade one quart to
one gallon sized pots when planting two gallon or larger sized containers.
Similar to perennials, many growers opt to use smaller liner sizes when
summer or fall planting and larger sizes when quick cropping shrubs in
the spring.
http://www.GPNMAG.COM
January 2020

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