If we limit our growing time to the number of days between our spring and fall frost dates, we don't have much time to work with here in Saskatoon, so every season, I continue to work on stretching our vegetable production beyond our frost dates. In this post, I will share a few specific examples of relay planting, which is one of the strategies we use to keep our growing space active for a longer period of time. When our growing space is active for more days, we end up with more production on less space, and I know a lot of you are after that same goal!
If relay planting is a new term for you, here is a quick primer. Relay planting is the practice of planting multiple crops in the same garden bed sequentially. That means after a first crop is harvested, another crop is planted immediately instead of leaving the space empty. If quick growing crops are used in relay combinations, it is quite possible to grow three crops to maturity in one garden bed, even in our short growing season.
Relay planting is a necessary strategy to employ in season extension, because stretching our planting and harvesting dates is not as simple as just planting our tomatoes a month earlier than usual and keeping them alive a month later in fall. We still have to give our crops the conditions they need to thrive, and shifting our warm season crops into the much cooler shoulder seasons would only end in disappointment. Therefore, our relay planting combinations will almost always involve the use of a cool season crop that we start earlier in spring or push later into the fall. Let's look at three specific relay planting examples from this season.
Relay 1: Peas to Beets
Peas and beets are two crops that can grow comfortably on either side of our frost dates, so this season we paired them up to occupy a single bed for an entire growing season. It made the most sense to use shelling peas for this larger planting since most of the crop could be frozen for our sinter supply. There is no way our family could eat this many snap peas during their harvest period so our snap pea plantings are much smaller.
The peas were seeded directly on April 29, emerged on May 10. The photo below shows a nice pea stand on June 4 after the trellises have been set up.
The pea harvest lasted from July 4 to July 14. This is a great time of year for peas to reach maturity. Later successions of peas often won't yield as well because of the hotter conditions of mid summer. Short harvest windows like this are good for relay situations, because the entire harvest can be gathered in just a few days. Then the whole bed can be replaced with the second crop in the relay.
The beets were transplanted on July 14, immediately following the last harvest of peas, and they would remain in the bed until their final harvest on October 11. I often transplant beets when I want an early start in spring or when I want to achieve the best spacing and uniformity. You can read more specifics about how to transplant beets in this Classroom post. In this case, the use of transplants allowed for the fastest possible transition from one crop to another because the first three weeks of beet growth took place in the nursery while the peas were still being harvested.
This relay combination works because both crops are capable of withstanding a few light frosts and both crops mature relatively quickly, but I still need to make sure the transition is quick. Starting beets in the field on July 14 would have left us with only golf ball sized beets in October, but if I start our beets as transplants we can finish the season with full sized beets. This relay sequence could be improved further by starting the peas as transplants as well. I have done this in previous years and harvested peas in late June.
Relay 2: Corn to Spinach
This combination pairs a warm season crop with a cool season crop, and it is pretty easy to accomplish because corn is one of the quicker growing warm season crops. Still, to get a little head start, I opted to start our corn with transplants. This allowed me to plant growing corn on May 29 as soon as the soil was warm enough.
On August 20, after 2 weeks of corn harvesting, the plants were removed and spinach was planted in the same bed. The challenge with starting fall spinach is that we need to plant it while the soil and air temperatures are still quite warm in August. We can still get great germination rates if we pre-soak and refrigerate the spinach seed as I explain in this Classroom post, but this year we caught a break with a cool patch of weather right when we needed to plant our spinach. It only lasted for about a week, but these cooler temperatures made it possible for me to direct seed our fall spinach and still get great germination rates.
The reward of this late planting was having an endless supply of spinach late into fall, and all from space that most gardeners would have left empty after the corn harvest. Our last harvest from this bed was October 29. This relay sequence could be improved further by planting a crop of lettuce or spinach before the corn.
Relay 3: Potatoes to Beans
To pull off this relay combination, I turned to the much warmer microclimate within our high tunnel. I used the high tunnel primarily to get an extra early jump on the potato crop. The added warmth of the tunnel allowed me to plant potatoes on April 1, which is a month earlier than our earliest field planting date for potatoes.
If I were to use this combination in an ordinary field bed, there would not be enough time to let the potatoes bulk up because I know that I need to plant the beans in the first week of July so they have time to reach maturity. While I could harvest a really immature crop of field planted new potatoes at the start of July, the yield would be so dismal that it would hardly be worth the effort.
One concern I had about planting potatoes in the tunnel would be excessive heat. Potatoes prefer growing temperatures between 15ºC and 20ºC and temperatures can exceed that range consistently in the tunnel even early in spring. I think the cool nights of June helped temper the heat for the potatoes and I did my best to keep the tunnel well ventilated to avoid big heat spikes. The crop looked healthy for its entire growing period, and eventually, the early start paid off with a harvest of 60 lbs on July 7. This yield far surpassed any early harvests of potatoes I had experimented with in the past, so I will be looking for ways to include early potatoes in our high tunnel again in the future.
As usual with relay planting, there was no time to waste, so our Roma bush beans were transplanted into the bed on the same day that the potatoes were harvested. By starting these beans as transplants, we could leave the potatoes in the bed two weeks longer and the bean plants could take advantage of their new space much faster than they could if we were to only plant them as seeds on the same day.
Eventually, the beans were harvested from August 24 to September 16, yielding 28 lbs. Both of these crops could have yielded more with ideal conditions. Had the potatoes been left in their bed to mature fully, I would expect a yield in the 80-100 lb range, and if the beans had prime mid summer conditions to fruit, I would expect a yield around 40 lbs per bed. However, given that I pushed both crops to their limits and kept my growing space active for more of the year, I am satisfied with these yields. It was a treat to harvest a large crop of potatoes earlier in the season because our storage potatoes were just finishing up and this new fresh supply meant that we didn't have to wait to fall for more potatoes.
I hope that the specifics I shared with these three examples have given you some inspiration to keep working on your own relay planting combinations. If you are growing close to us on the Canadian prairies, then you may find that these three examples work well for you as well, but ultimately, it will take some practice to reach the full potential of relay planting in your growing space. Every site has unique qualities that you can master only by pushing the limits and keeping diligent records. I feel like I have said this before : ) If you would like to take the fast track and refine your skills in a supportive community, learn more about how you can grow with us here.
