Hi Toronto Master Gardeners! I am a graduate student completely new to gardening and would like to please seek your advice on my very first gardening project in terms of (A) planter construction and (B) correct plant selection. I have attached 2 pictures to guide you – actual site and proposed planting scheme (please excuse the mess – it just finished raining and I am still looking for a nice outdoor rug to cover the uneven concrete and still have to install the sofa seat cushions). Thanks in advance!
(A – PLANTER CONSTRUCTION) I have just finished a DIY project of 2 long wooden planters (each one measuring 60″ long x 18″ wide x 12″ interior soil DEPTH) which have been positioned on a concrete patio and against a brick wall (EAST facing – it gets morning sun and starts to get shaded by the house by about 12noon). I have ensured that the wood planter is raised from the ground / concrete pad (by about 3 inches), lined with thick contractor plastic to avoid wood rot, and has adequate drainage holes (qty.12 – 1 inch holes and qty. 12-1/4 inch holes which I plan to cover with a few large rocks/ pea gravel and line the entire base with landscape fabric for smooth drainage without any soil coming out of the box). I have also positioned 1 hanging basket bracket and qty.2 – 6ft tall wooden trellises on each of the planters as I would like the brick wall to become very lush with plants. I understand that I should also only use potting soil for these planters. Given all this information, am I so far doing everything correctly in terms of the “construction basics” for planter / container gardening?
(B – PLANT SELECTION) – With the planter, trellis and wall bracket now in place as well as given the planter size / dimension and position (east facing), may I please ask you for your comments if I am selecting the right plants for the space. For the two hanging baskets – I plan to get a pair of hanging ferns (I plan to care for them indoors during winter to make them last). For EACH planter (size: 5 foot wide x 1 ft soil depth) – I was thinking for of planting one “endless summer” HYDRANGEA right in the middle, “sweet autumn” CLEMATIS on each side of the planter (each one in front of each trellis panel) and 2 smaller HOSTA (each one located between the central hydrangea and side clematis as filler and to keep the roots of both plants cool). I was also thinking of planting some BOSTON IVY behind each HOSTA, (which I also promise to carefully monitor/ control and intend to train to climb the 6-foot tall trellises in combination with the flowering CLEMATIS) so that I get to have a lush green wall much faster and for a longer period of time compared to having only the clematis as the only vine. I chose these plants because they are mainly Perennials (more friendly to my student budget as I cannot really spend on plants every year) and because I read somewhere that they are good for container planting and “hardy” for Toronto (I intend to leave the entire planter in the same spot as I have no storage shed – to protect the plants over winter, I can bubble wrap the entire planter or maybe relocate some of them on the ground during late fall to protect from frost if needed). Given the lush “look” that I want to achieve, the size of my containers (5 ft. wide x only 1 ft. soil depth) and its orientation (East facing), are the plants I intend to purchase the appropriate choices and will most likely be successful? If not, what alternatives for the central shrub (Hydrangea) and vines (Clematis and Ivy) do you recommend? I read somewhere that Clematis might need more than 1-foot soil depth to grow the entire 6 foot trellis I have so this is a concern to me and that if the Clematis definitely won’t work given the limited planter depth, I can also just find another perennial or even an annual flowering vine to plant each year that I can intertwine with the planted Ivy (any more flowering vine recommendations for shade please)? I am honestly very excited to purchase and plant this long weekend but will wait for your response and advice to make sure that my gardening budget is well spent on choosing the best and most appropriate plants for the space and planters that I have. Hope to hear from you. Thank you!
Thank you for contacting the Toronto Master Gardeners with your question on your container garden in the making.
First congratulations on your diligence in researching the topic, as this will add to your long term success an enjoyment.
The construction and material you’ve assembled will provide good drainage and support. The planting medium is essential that you use a quality potting mix. Bubble wrap will be a good idea for winter protection, as well as your ideas about placing on the ground in winter time to provide a more stable temperature. The biggest risk for the container in winter time is freezing and thaw cycles, improper moisture levels. During winter months, shrubs often suffer from moisture loss (dessication) if they can not pick up enough moisture, especially before dormancy and freeze. Wind protection will also help minimize moisture loss. Having too much moisture will also create root rot or fungal issues.
If you do choose any evergreen, it is wise to spray a coating of anti-dessicant on the leaves.
You have some nice ideas on the design and layout of your container box. The concern you mentioned on Clematis is well founded because they are sensitive to having their roots heated up in the summertime.They like cool roots, and I think this would prove difficult in a container box receiving direct sun even for half the day. Your container might be large enough to moderate temperature fluctuations, however if you want to give this a try, it would be advisable to have other plantings in front of clematis, so as to provide shade for the roots.
So other ideas for a vine which can produce a longer bloom display and will fit the size of your trellis;
Morning Glory, Mandevilla, Black-eye Susan vine,
Other than Clematis, there are not that may choices for climbing vines which provide bloom, that will fit the confines of your trellis. Purple Japanese Honeysuckle provides trumpet like blooms from June to July and stays under 10 feet.
Other climbing shrub like vines which can also provide some variegated leaf interest year around include; Euonymous Sarcoxie or Euonymous Purple Winter Creeper which can both be trained to climb a trellis.
Some other ideas you might want to consider include the use of ground covers which can cascade or flow over the edges of your containers. Creeping Jenny (Lysimachia) comes in a lime green or medium green and has a yellow flower. Lamium can also provide a nice variegated cascade affect. Some of the Sedums can cascade as well. Have a look at yellow-flowered Sedum sexangulare, or even hens and chicks (Sempervivum spp. and cvs.).
The use of a grass like golden variegated Japanese Forest Grass can offer fine a flowing texture with colour interest as well.
I hope you have picked up a few more pointers and verification that your on the right track to have a beautiful container garden.
Enjoy your project and your garden !