We will provide an introduction to topics such as STEAM, meteorological versus astronomical seasons, frost dates, etc. as a prelude to our March 2022 garden education podcasts.
Gardeners, please find more information about some of the topics that were covered very briefly in this short episode.
The USDA Hardiness Zone Map is here and you can see why typically we say that Chicago lies in hardiness zone 5/6 as the map depicts a small sliver that finds us in zone 6. There are a couple of reasons for this first Lake Michigan has a modifying effect and second, there is the urban heat island effect, thus Chicago can be warmer than the surrounding area. However, plants designated for zones 5 and 6 generally do well.
Also, season extension strategies such as greenhouses, high and low tunnels, etc can simulate conditions in warmer zones thus extending our season and making it possible to grow some plants that may not otherwise thrive in Chicago.
Hardiness zones must not be confused with frost dates and in fact, I have seen the last frost dates for my zip code range for mid-April to mid-May. We use April 30 as our last frost date, but note if you start seeds (also see by zip code) and the weather is not suitable for transplanting you should still have a two-week window. In other words, your seedlings will thrive until transplanted two weeks or so later than your projected last frost date. You may check for your potential last frost date by entering your zip code, but also read the notes of the site.
Now you can utilize the last frost date to calculate when to start seeds should you decide to do so (seed start tips). This chart uses a May 20 last frost date for example but it is also in line with what was stated earlier in terms of using a frost date around April 30. Note also, we recommend using the early seed start and transplant dates for broccoli, cauliflower, cabbage, and spinach in particular due to the opposite possibility of a stretch of warm weather happening in May that may cause these particular plants to bolt. In fact, I recommend with the exception of spinach as a fall crop, on the other hand, hardier crops such as, collards, kale, and chard do well transitioning from cool to warm weather. Spinach on the other hand germinates and can be harvested pretty quickly and easily replaced with a warm-weather crop.
This brief episode and the information should assist you with getting started for the season. Another episode will drop in early March 2022 providing more in-depth garden education information. Until then think spring! If you have questions please contact, firstname.lastname@example.org.
Bonus Content: Seed Start Videos From Joe Gardener and MIGardener