Constructing The Winter Pots

the winter pots (1)If my last post was convincing enough to make you entertain the notion of filling your pots for the winter, you might appreciate a description of our process. Every pot begins with dry floral foam.  I cannot really explain how liberating it is to have foam, and not soil as a medium, except to say that that a soil base dictates the overall shape. We take the soil down in all of our pots 4 inches, and put a thick layer of foam in top.  In big pots, we may anchor the foam with steel rebar driven down into the soil. A winter pot needs to stand in spite of winter wind and snow. I like greens that are much wider than the pot. That generously sized blanket of greens has warmth written all over it. No soil based construction can deliver much in the way of width.   Constructing a winter pot on site in freezing weather is slow and uncomfortable.  It is just about impossible to clean up.  We make the mess in our garage, and only go on site to install. A garage heated to 50 or 60 degrees means you can concentrate on what looks beautiful, rather than the cold that is making you miserable.

the winter pots (9)We buy the dry floral foam by the case, in big sheets. But craft stores usually carry dry floral foam in bricks. The bricks will need to be glued up with hot melt glue. If you use bricks, floral picks or skewers can be used to further secure all of the pieces.  Wedging the entire assembly into the top of the pot will also help keep it together.We use a giant wood compass to scribe the interior diameter of the pot on the foam.  We glue 2 sheets together. The bottom sheet  goes in the pot.  The top sheet goes above the rim of the pot, and will have evergreens stuck all around the edge into it. The width of those greens all around the edge of the pot will determine the proportions of every other gesture. Ready to stick?

the winter pots (3)We sharpen our greens down to the wood with the blade side of a pair of pruners. Stuffing an evergreen stem with the needles still on it means the hole in the foam will eventually be too large.  As the needles loose moisture, they will shrink. A heavy bough in a hole that is suddenly too large may fall out.  We only insert sharpened wood into the foam. A tight fit is a fit that will last throughout the winter, no matter the weather. When we have a lot of pots to do, we have at least two people who sharpen evergreen stems.  We buy evergreen tips that are 18″ long. Short evergreen stems suitable for wreaths and table arrangements are not long or hefty enough for what we do.

the winter pots (2)Stuffing the stems into the foam is an art. My landscape crew does an incredible job of it-better than I could.  All their years planting means they have a feeling for how the cut stems should look in a winter pot. They need to have a loose and natural look. This is not to say that we do not do more contemporary pots that are more about design generated by the human hand than nature. This client prefers a more natural and traditional look.

the winter pots (6)A bamboo stake marks the approximate location of the center of the form. We leave a big empty space in the middle-that will be cut out to hold the centerpiece. Or perhaps the centerpiece is comprised of twigs or picks set individually. If we set a big centerpiece through the greens foam, we will have to go back and stick individual evergreen branches around that centerpiece to soften the transition from the horizontal plane to the vertical plane.

the winter pots (5)We have 2 very large pots to dress for winter on Monday.  The outer layer is noble fir.  The inner layer is mountain hemlock. What else will go in these greens to to be determined.  It could be the large leaved German boxwood. It could be branchy twigs, or pine cones. It could be mini grapevine garlands.  It could be no end of winter and holiday picks. The greens are the foundation upon which all else will be built.

the winter pots (7)All of the fir family branches hold up and sail through the winter.  Even winters with heavy snow. The mountain hemlock is the toughest green I have ever used.  The stems in my pots on my driveway were as green and lush the end of March as they were in November. For gardeners that live in northern climates, the longevity of cut greens is important. I stay away from cedar and white pine. They dry out and turn brown so fast.

the winter pots (10)Some winter and holiday pots begin with the centerpiece. These are some pots that need something other than a center of interest. They need a wider ranging area of interest.  The floral foam is a perfect medium for this.

the winter pots (4)This arrangement will go in a rectangular pot. That rectangle is a strong geometric shape that asks for an answer that resonates. We set the center in some pots before the edges. Why? The foam will adequately hold a shorter centerpiece.  A very tall centerpiece has a bamboo stake which gets driven down in to the soil for stability. It goes through the foam, it is not supported by the foam.

the winter pots (11)This center is diffuse., but roughly rectangular. The red berry picks and plum eucalyptus make for a mix of reds that is interesting.  The port orford cedar is a strong contrast.  We will finish the edges with mixed evergreens, with lots of port orford cedar in that mix. Anything else? I am not sure yet.

the winter pots (8)Winter and holiday pots are not all that we do.  The place where today’s pots will go have a garland to go over the door.  We buy garland, and then zip tie our evergreen boughs to it. This doubles the heft, and the places where other ornament can be attached. For winter, I like every gesture to be generous and warm. I would not want to be resigned to the coming of the cold and the gray skies. I would rather fend off the dark and dreary in whatever way I could.  This garland gets set on an army of cardboard boxes, so the work is at a convenient height. Convenient to see and think over, and convenient to work on. I will so enjoy all the making that lies ahead.

Sticking It: A Foam Story

dry-floral-foam.jpgOur late fall weather took a nose dive a few days ago.  Just yesterday, it was 15 degrees when I came into work.  Bitter cold like that over a period of time can make any soil left in a container turn rock hard.  I have had gardeners in, wondering how they will get their winter containers done.  We do not stick any of our greens into the soil in a pot.  Evergreen boughs installed in the soil have only one direction possible-that is straight up.  We build forms from florist’s foam that fit tight into the pot.  The foam will stand above the rim of the pot, enabling the placement of greens to the side, and on an angle.  Once a form is built, you can reuse it, or patch it.  But another great feature of working in foam is the fact that frozen soil is not a problem.

dry-floral-foam.jpgI try to remember to take 4 ” or so of soil out of the pot when doing the fall cleanup.  The bottom layer of the foam will sit down into the pot.  The top layer gets the evergreen stems. Very large pots may ask for more layers of foam.  Given very large pots, or very tall centerpieces, we may wrap the foam with steel wire.


We glue our layers of foam together with hot melt glue. Since the glue cools and sets up fairly quickly, we usually have 2 glue guns going at once.  If this sounds like way to much work, we make forms to order all the time.

layers-of-foam.jpgThere are plenty of variations on this theme. A long window box may ask for 3 forms that can be wedged together upon installation.  Odd shaped containers may ask for foam bricks that can be glued up, rather than sheets.  Some forms are thicker at the back than the front, if the materials at the back will be heavier in the back.  This material enables the actual sticking of the greens to be done indoors.  I would dread having to insert branches into half frozen soil when the temperature is much below freezing.  This would make the job miserable.

gluing-the-layers.jpgGardeners are routinely victimized by the weather, but in this particular instance, there is no need.  Being comfortable means the ability to concentrate on the task at hand, rather than the wind chill.  Should you want to move a branch over or up an inch, that adjustment is easy.  You can control the angle and direction of the placement with ease.  If you make a move you don’t like, you can try a different move.

winter-window-box-under-construction.jpgMuch better this mess on the garage floor, than on the front porch.  This is easy to sweep up.

dry-floral-foam.jpgThis is the third year for this form.  We actually don’t make so many holes in the foam.  We sharpen the woody stems of the greens with pruners.  This makes for a tight fit.  We look at the green topside of a branch to decide on the placement of the next.  We do not place the woody stems close together.  This helps to conserve material without sacrificing a lush look.

winter-window-box.jpgTransporting an arrangement this large takes some doing.  And the heaviest stems or centerpieces are put in once the foam is in place.  Once you get the hang of sticking the foam, there will be no stopping you.


If you haven’t done your winter containers yet, don’t despair. A little simple technology can help make it happen.  I did post lots of pictures of winter pots on the Detroit Garden Works facebook page today, should you be interested.