Riverdale Hub – Rooftop Garden*


Hello, I am looking to extend the growing season, as well as proactively planning for closing our rooftop garden.

We currently have tomatoes, kale, lettuce, carrots, and more growing in our several raised planters. We would love it if it were possible for a volunteer to aid us in this, but if not, an answer would suffice. Our soil varies for the plants we have, but it is generally dry and has ample sun exposure.

Thank you. I will look forward to your response.




Thank you for contacting the Toronto Master Gardeners with your question on extending and closing your  rooftop vegetable garden. What an exciting project to partake in !!  Hopefully this answer will aide you in your quest as the Master Gardeners generally do not do on-site volunteer work.

First on extending your garden season.  The best way to extend the garden season is to rotate in “cool weather” crops later in the season. I see you already have kale which actually tastes better after is has gone through a frost, and will last quite well in temperatures below -3 degrees C.  I have harvested leeks in January in temperatures down to -10 degrees C. !  Spinach is another cool weather crop that you can harvest well into frost, and will even last overwinter util spring. Other brassicas such as collards and swiss chard can also endure frost.  So part of your crop rotation and succession planning will go a long way towards extending your season.

There are also structures you may use to protect late season crops from frost or cool nights in order to extend you season. These can include cold frame covers or plastic covers, which can be opened in daytime to allow proper ventilation.  In addition to these structures, small greenhouse can also be instrumental in extending the beginning of the season by supporting growth of seedlings well before outside growing conditions allow in the springtime. I’ve included a link below to our Toronto Master Gardeners Guide on the use of cold frames.

Extending the Season with Cold Frames

Secondly , planning the closure of your garden:

Closing of your garden depends on the type of soil you have as well as what methods you adopt for maintaining the soil.

So whether you have used a synthetic soil or a natural soil, and how you plan to replenish nutrients or use mulching methods can dictate how you close a garden.

When you say you have raised planters, depending how large they are , or if they are actually raised beds, or individual planters which are small enough to empty and clean may require different approaches.

I have attached a few websites links below which provide some valuable insights on maintaining soils in raised beds, and can lead you to best decisions which best meets your setup.

How to Grow Vegetables in Containers

Container Gardening Guide

I hope this helps and wish you  a very enjoyable and productive garden!