Articles, Blog

Planting Boxwood Hedges in Historic Gardens

November 7, 2019


Chatham Manor, Fredericks burg, VA currently
part of Fredericksburg & Spotsylvania National Military Park The property dates to the 1700s. This garden was designed by Ellen Biddle Shipman
and Charles Gillette in the early 20th century. The garden that visitors see today was redesigned
in the 1980s. Over several days, a National Park Service
team replanted missing historic boxwood hedges in the garden.
Boxwood Selection The cultivar selected for planting was Buxus
microphylla var. japonica ‘Morris Dwarf.’ “Morris Dwarf”
• Very low maintenance, compact growing cultivar
• Ideal for edging formal gardens because of its smaller size
• Requires very little pruning • Few pest or disease issues
Jamie McGuane (Olmsted Center for Landscape Preservation; Preservation Arborist):
Now that we’ve selected the cultivar to plant in the Fredricksburg Garden at Chatham,
we’re going to now look for healthy plant material. So here’s a nice looking boxwood.
You tell it’s got a nice green, dark green color, not a lot of dead on it. It looks very
live and vigorous. We don’t see any signs of insects or disease within the plant so
that’s a good sign for us. I stick my finger down in the plant and I can tell the plant
is nice and moist so they’ve been watering it, so that’s good. These plants haven’t
been drying out. Now if I squeeze the pot and take the plant out, I can take a look
at the root mass. And you can see on this plant, there are some girdling roots on it,
but it’s got a lot of good live roots and nothing that we can’t fix in the field by
a couple of cuts. Girdling roots form on the plant when it’s left in the pot for too
long. The roots like to grow out, and when the roots can’t grow out, they start spinning
around the pot and they wrap around the plant, and that girdles the plant. It could get up
to the point where it would girdle the stem and kill the plant, but this is just not good.
You don’t want plants that have been left in the pot for way too long. They should be
potted up to the next size pot if they’ve been in the pot for a long time.
Healthy Boxwood: • Dark green color
• No insects or disease on plant • White or light colored plant
• Minimal girdling of roots Unhealthy Boxwood:
• Dead or wilting leaves • Unhealthy appearance that could mean disease
• Dark brown or dried out roots Preparing Planting Trenches
Plants growing along the garden edge were carefully lifted.
The plants were transplanted elsewhere in the garden to make space for the new hedge. This morning we’re going to be planting
boxwood in a hedge in the gardens here at Chatham. We’re going to be doing that in
trenches to place the boxwood about one foot apart from one another on center. By that
I mean that we’re going to actually be placing the boxwood 12 inches apart from center of
plant to center of plant. We’ve prepared a trench to actually plant the boxwood and
the trench was first dug with a pointed shovel to create the depth that we’re going to
be planting the boxwood at and that will be about 5 inches below the existing grade of
the garden. After we rough dug the trench with a pointed shovel, we came in with a flat
spade to actually cut the edge to create finer and more distinct lines. Then we graded out
the trenches you can see its relatively level to about 5 inches again below the grade of
the garden. Now when we plant the boxwood, they’re actually going to be coming out
of their containers at different heights and when we remove the top portion of the soil
to expose where the root flair or where the roots begin at the base or the stem of the
boxwood. Those are going to be at slightly different levels from plant to plant so when
we actually go to position the plant in the ground some of the plants we’re going to
have to put some soil below these root balls in order to get them to the correct height.
Others we may have to dig a little bit further into the trench to get them to the correct
level. But this is how we’re going to prepare the remaining 3 trenches in the garden to
plant out the complete hedge along each of these 4 garden beds. Setting an Alignment Line We’re going to be planting a boxwood hedge
in this pre-dug trench, and we want to make sure that each of the plants are 8 inches
off of the edge of the existing garden bed, so using a tape measure I’m going to measure
in 8 inches off of the existing edge and put a stake in at the beginning of the trench.
From here I’ll put a second stake in midway down the center of the trench, and I’ll
attach a string
between this take and the next one down the row. So once this string is actually attached
between the stakes at the center of the trench, we’ll use it as a guide to make sure that
each of the plants is centered to one another and exactly 8 inches on center from the edge
of the bed. Planting Demonstration
So now we’re placing the plants into the trench to layout the hedge and in order to
plant them accurately within the row we have a few homemade tools that we’re using in
order to properly space them. First, we have used some available staking bamboo to mark
out 12 inch increments. Those 12 inch increments are being used from the center point of each
plant to the center point of the next adjacent plant so we’re sure that they’re each
12 inches on center. Secondly, we have previously installed a line that’s exactly 8 inches
from the edge of the planting bed to the center point of each plant. So using these 2 tools,
we’re able to make sure that we have plants spaced 12 inches apart and 8 inches in from
the edge of the planting bed. In order to make sure that we’re planting at the proper
depth, we’re using a garden stake to identify across the width of the trench that we have
previously dug- the depth at which we want the plant to actually be installed into the
ground. (Once planted, the top of the root ball should
sit just above the grade of the surrounding garden.)
The planting process involves taking the containerized plant and first step would be after removing
the plant from the container is to remove the top soil that may have accumulated at
the base of the stem, just to expose where the roots initiate from and that’s usually
about, in the case of these boxwoods, about an inch or so from the top of the root ball
as it came in from the nursery. Then as we can see there are a number of circling roots
around the base of the plant. All the roots are very healthy, but the circling root pattern
will continue to grow that way unless we break it apart. So there are number of different
ways we can do that. We can tease them apart with our fingers and pull them out and break
up that circling, or we can a soil knife or utility knife and in 3 or 4 areas around the
circumference of the root ball we can sever the roots as well. From there, we place the
plant using our story board, 12 inches distance from the prior plant that was planted into
the trench. And then we use the stake to make sure that we have the plant at the correct
depth. And the depth we’re really looking for for these boxwoods is about an inch to
an inch and a half above the grade line. So in this case I’ll move the stake to this
side. You can see that we’re about an inch and a half above the stake which means that
we’re about an inch and a half above the grade of the garden to either side. This is
because the hole we dug as part of the trench isn’t very compact, and this soil will settle
over time and as such the plant itself will settle into that planting hole. So our intent
is that the plant will settle to where it matches up with the existing grade of the
garden over time. So that’s a good planting depth. It’s on the center line down the
center of the hedge and it is 12 inches away from on center from the adjacent plant. So
now we’re ready to fill in soil around it. The soil in this garden has a little bit of
clay in it so it’s clumped up a little bit. Take that soil and we place it around the
base of the boxwood and we firm it into place. And we’re ready to move onto the next one. Fertilizer
We just completed planting boxwood in a row to form a hedge along the edge of this garden
border. Just prior to planting, a soil test was conducted to see if we needed to adjust
any of the nutrient levels of Ph of the soil. It was determined that no adjustments were
needed. However, there were a number of wood chips that remained in the garden bed that
were incorporated into the soil that couldn’t be removed as the holes were being dug and
the trench was being prepared for planting. When wood chips remain in the soil and they
begin to decompose, they draw nitrogen from the soil and make it unavailable to the plants
to feed the decomposition process. In order to compensate for that, we are applying a
10/10/10 fertilizer, 10% nitrogen, 10% phosphorus, and 10% potassium in order to support the
decomposition process, or offset the nitrogen that’s used for the decomposition process
while the wood chips are decomposing in the soil. So we’re just going to apply a very
small amount of fertilizer around each plant and cultivate it into the top surface of the
soil. This fertilizer will wash into the soil as the plants are irrigated. Once the fertilizer
is applied, we will irrigate it in, water it in and also gently wash off the plants
to make sure any fertilizer that may have ended up on the foliage is washed off. After
watering the plants in we’re going to then come in and apply a very thin layer of about
one to one and a half inches of mulch to keep the weeds down and help the plants establish
themselves by creating or developing good root systems in the soil. So we’ll continue
to mulch the bed and the hedge route along the entire length and we’ll irrigate the
plants in once more and let the plants grow and develop into a hedge.

5 Comments

  • Reply Greg R April 17, 2016 at 2:59 am

    Please wake me up when the instruction begins.

  • Reply Daniel Modarres June 16, 2016 at 10:47 am

    Caveboxbushes

  • Reply Daniel Modarres June 16, 2016 at 10:50 am

    Straighyboxbushes

  • Reply Kenzie Dahlgren July 3, 2016 at 11:36 am

    We are just about to go and plant a 70' boxwood hedge and this video has answered any remaining questions we had. Thank you very much!

  • Reply Runcible2010 October 18, 2017 at 11:27 pm

    Should dwarf English boxwood be planted 12 inches apart from center to center, as well? Thank you!

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