We're back with another round of vegetable growing lessons after our 2019 season. No two seasons are ever identical so there is always something more to learn. In case you missed it, here are our top 10 lessons from 2018. This year, we have a few new experiments to report back on as well as some improved techniques to share. Read on to learn more.
Lesson #10 - A Sour Experience with Sweet Potatoes
Sweet potatoes are most productive where summers are long and hot. Therefore, I didn’t have high hopes for this one in our zone 3 conditions, but local growers ask me about sweet potatoes often and I also really needed to satisfy my curiosity! Since we had a little extra space in our high tunnel this season, we decided to give them a try in the warmest conditions we could offer. The variety we grew was called Covington which was marketed as one that could produce well even on the Canadian prairies. We purchased pre-started sweet potato seedlings (a.k.a. slips) to transplant into our high tunnel. The slips are very sensitive to cold temperatures so they are only shipped in late spring. We transplanted our slips on June 10th and spaced them generously with 3 feet between each plant. The growth of the vines began quite slowly but they would eventually sprawl over their entire raised bed. On October 11th, 120 days after planting, we harvested 2.75 kg in total from our 4 plant trial. Roots were long but quite skinny. In a longer season, harvest would wait until the plants started to turn yellow, but in our case, freezing temperatures forced a harvest while plants were still fully green. One of the sweet potato studies I read described a trial in Quebec, Canada, and reported yields ranging from 0.75kg per plant when they were spaced 15cm apart to 2.85kg per plant when they were spaced 60cm apart. Our plants only yielded 0.69kg each with 3 foot or 90cm spacing so they clearly underperformed. This initial trial was enough to satisfy my curiosity about whether or not sweet potatoes could be a productive crop in our high tunnel. I think we could get off to a better and earlier start by growing our own slips and that might lead to more reasonable yields, but we’ll always have our cool short season working against us. Until we have time and space for another trial, this crop will be on the back burner and we’ll focus our energy on crops that we can count on to produce more food for our household.
Lesson #9 - Pole Beans Climb to the Top of Our List
I delayed adding pole beans to our crop list for years because I wasn’t keen to set up trellises for yet another crop if we could get by with bush beans. However, when I read about the characteristics of Fortex beans, I just had to give them a try. Fortex beans are a French filet pole bean that can comfortably reach lengths over 11 inches. We generally harvested them at around 10 inches, and if you wish to enjoy them when they are shorter and thinner, they can also be harvested in the 6 to 8 inch range. The beans have a sweet flavour and a wonderful texture that I want to describe as full and meaty. These are solid beans. They don’t just flatten in your mouth when you chew them and we really liked that quality. There were two main questions I had before growing: 1. How well would they respond to growing on our 5 foot high trellises? Pole beans would easily take advantage of a 7 or 8 foot high trellis but I’d rather not cast that big of a shadow in our garden and it’s always easiest to stick with the equipment you’ve already got, so I challenged them to grow on our standard 5 foot high field trellises. The vines had no trouble reaching the top of these trellises and when they got there they seemed content to wander around the top rail a little and then wind themselves back down. 2. How would the total yield compare to bush beans? Our Fortex bean trial gave us a yield of 25kg from one of our standard 50 square foot beds, slightly higher than our typical yield of 20kg per bed for Roma bush beans. This harvest was extended over a period of a month, unlike bush beans which typically offer their entire harvest over a period of 14 days. What is extra promising about this trial is that we started this crop late with a seeding date of June 12. With the ongoing productivity of pole beans, yields will only increase if we give them a longer season so I am excited to plant this variety again next year with a much earlier start. You can find more information about Fortex beans in the Crop Profile section of our online Classroom.
Lesson #8 - Consistency in the field starts with consistency in the nursery.
When raising your own transplants from seed, it doesn’t take long to notice that the plants that have the best start to life end up being healthier in the long run and more productive in the long run. The opposite is also true. If a plant struggles early on, it is unlikely that it will ever catch up to others that enjoyed a better start to life. With our brassica crops (primarily cabbage and broccoli) the difference in plant health and vigour is particularly important to us, because we want a patch of cabbage to yield a bunch of similarly sized heads at the same time. This way we can share them harvest with our farm members at the same time and give everyone the same quantity. Experience has taught us that this consistency we desire is actually something we can control, and it starts in the nursery. The big change we started making this year is to cull a lot of our brassica seedlings at a young age, meaning we seed a lot extra and only plant the best in the field. We now start our brassica seeds in 3/4 inch soil blocks and soon after pot them up to 2 inch soil blocks. Starting a lot of extra seeds in 2 inch soil blocks would be wasteful, but the 3/4 inch blocks are really quick to work with. Once the seeds germinate, it doesn’t take long to notice which plants are the strongest. We select only the best to pot up to 2 inch blocks, and from then on the consistency is pretty much guaranteed, as long as we control other variables like water, spacing, soil quality, and light exposure. .
This practice of culling has been great for our brassica consistency but it certainly would apply to all transplants you start at home for your own garden such as tomatoes, peppers, squash, cucumbers, onions, etc. It’s just a matter of deciding when it worthwhile for you to invest a little more resources up front to have improved vigour and consistency in the long run. At first, it’s hard to toss the weak seedlings in the compost, but when you see the consistency you are rewarded with, you’ll be hooked.
Lesson #7 - Melons in the House
I was excited to do a trial of melons (watermelon, cantaloupe, and honeydew) in our high tunnel this summer after seeing their less than impressive performance out in the field in previous years. (Remember we’ve got short cool summers here in zone 3.) Here are a few things we learned along the way. We trellised each plant up a single length of twine mostly by winding the vine around the twine but occasionally supporting the vine with tomato clips as well. Melons send out secondary leaders so these need to be pruned so that the plants just focus growth on one main stem. Once the vines reached the top of our 7 foot trellis, we just let them wander around up there and kept things pruned tidily down below where the fruit was hanging. This trellising system worked really well. Because melons are a lot heavier than a single tomato or cucumber, they need to be supported when growing vertically. The trick we used for this was to enclose each melon in an expandable mesh sack and clamp that sack on to the trellis twine with a tomato clip. This also worked really well.
We limited the number of fruit on each plant to 3 at the most. The number of fruit to keep was a bit of a gamble based on research I had found previously. You don’t want to let too much fruit set on and have it not ripen in time, and you also don’t want to prune too many fruit off and unnecessarily lower your yield. With our spacing of 1 plant per foot, pruning to 2 fruit per plant may have been more appropriate, but the general idea of pruning excessive fruit worked out well. The last big factor we were curious about was the yield. How many melons could we produce per square foot and would it justify the use of space in our high tunnel? Well, the answer was 67kg from the 100 square foot bed we used for melon production. From that same amount of space, we could have harvested over 200kg of cucumbers so it’s obvious the melons didn’t earn their keep. They’ll have to be downgraded to the “grow just for fun” list.
Lesson #6 - Patience pays with potatoes.
I have a hard time waiting for potatoes to mature. By mid summer our last season’s crop is likely gone, or if not it has most certainly sprouted and become undesirable after so many months in storage. We see our new potato patch get bigger every week and start to dream about sinking our teeth into the oh so moist first potatoes of the season. . The debate is how long to wait. We know that tuber formation has begun when the plants are flowering, but if we wait longer, how much bigger will the potatoes get? What’s at stake by digging early? I have kicked myself for digging up early beds of potatoes many times over in the past. I actually came across a note in my farm logs today that strictly read “Don’t plan to harvest mid-season!” It turns out that a rather big difference in yield is at stake. Those new potatoes come at a cost!
In the image above, I shared some data from potato field trials published by the University of Saskatchewan Vegetable Program. Note how the yields continue to increase to 120 days after planting, even for so called “early” potatoes! In our zone, we typically plant potatoes in early-mid May so a harvest 120 days later would be in mid September. That means all those times I have grown impatient and pulled beds of potatoes out early, I have left something on the table..or rather sacrificed potato yield that will never make it to the table. This season, I finally exercised some restraint with our potato beds and just as the research shows, we were rewarded with more potatoes! We especially enjoyed higher yields on some of our mid season specialty potatoes like AmaRosa and Rosemarie. Here are some stats from our own records showing Marilyn potato harvests from 50 square foot beds at different stages in the season. Yield - Harvest date 11 kg - July 22 41 kg - September 1 47 kg - September 8 65 kg - September 21 So will we ever dig potato beds early again?..on occasion, but only when we have other crops to plant the same space. We now have a better understanding of the true cost of an early harvest.
Lesson #5 - Regular Broccoli vs Sprouting Broccoli
I have shared a bit about our trial of sprouting broccoli earlier, but I haven’t said much about our regular broccoli trial. We grew that too, and now that we have records from both crops, we have a chance to look back and compare the two. The broccoli variety we grew this season was called Belstar. It has a reputation of of being able to grow well in a wide variety of conditions, mature relatively quickly, and offer good side shoot production, that is the additional growth of smaller heads after the main head is harvested. I was curious to see how the secondary growth of Belstar would compare to the secondary growth of our sprouting broccoli. So after the first heads were harvested pretty much right on schedule, 60-70 days after transplanting, we let the plants keep growing to produce side shoots.
While the first heads were quite beautiful and consistent in size, the secondary shoots that followed were very irregular. Some secondary heads were small and attractive and others were large and tiered with bead size at different stages (above). The secondary harvest ended up being quite large as you can see from the graph below, but since a lot of the heads were unattractive, the large volume wasn’t that valuable to us.
The lesson learned from comparing these two varieties of broccoli was a clear one. If you want a large harvest at a predictable time, plant regular broccoli, and if you’re picky about appearance pull the plants after the first harvest and plant another crop. Alternatively, if you would prefer to harvest a slow but steady flow of tender broccolini stems all summer long, plant sprouting broccoli.
Lesson #4 - Breaking the Rules Growing Carrots
In recent years, we’ve been pushing our first carrot crops earlier and earlier thanks to improved planting techniques. The changes we have made now give us a dependable carrot harvest a month earlier than our first carrot crops of the past. As a result, I began to wonder if we could possibly growi two carrot crops to maturity in the same bed in the same growing season. I couldn’t resist giving it a try, and I am pleased to report that we pulled it off! This feat may not be that remarkable for many of you in warmer areas, but we are in zone 3 with quite a short frost free period, May 21 to September 15 on average. If you would have told me years ago that a double cropping of carrots in the same bed was possible, my jaw would have dropped in disbelief.
Here’s how we did it. We started the first bed as soon as we could using the soil warming techniques that I describe in our online Classroom. This soil warming in early spring is critical for the carrot seed to germinate quickly. Without this effort, the seed would lay dormant waiting for warmer conditions, but with a little extra attention to warming the soil, we can coax our first carrot seedlings to emerge before the end of April and harvest our first crop by the end of June. We also knew going into this challenge, that we could delay our final carrot planting to the end of June and still expect full sized carrots late in fall. So this time around, when we pulled out our first carrot harvest, we simply planted another round for a fall harvest. We used Mokum carrot seed for this trial and here are our seeding and harvest dates: Crop 1 Seeding: April 8 Crop 1 Harvest: July 2 Crop 2 Seeding: July 2 Crop 2 Harvest: October 7 This double carrot cropping breaks two common beliefs about vegetable growing: 1. Don’t plant your garden until the last frost, and 2. Don’t plant the same crop in the same place consecutively. It turns out that some common gardening beliefs are misconceptions and it’s a pleasure push through these barriers.
Lesson #3 - Big Gains in Strawberry Production
For years, we had a small patch of strawberries in our backyard, but it wasn’t well organized, weeds were difficult to control, the plant spacing wasn’t consistent, and we never had a logical way to rejuvenate the patch. As a result, there weren’t many strawberries to pick, and that takes a lot of the fun out of growing strawberries. . More recently, we increased our strawberry production by devoting some of our large standard sized vegetable beds to strawberries. This forced me to do the research and figure out a soil based system that would be productive, low maintenance, and sustainable year after year. Now, I am happy to say that we can grow as many strawberries as we can eat! . This season we were finally able to get some good records and refine our strawberry growing methods so that they work really well within our vegetable bed layout. Our strawberry patch is no longer an unproductive area of neglect in our garden. It’s organized neatly and contributes its share to our overall harvest. I love that the timing of our June bearing strawberries fills a gap in our garden production early in the season, I love how little maintenance the strawberry patch requires when done right, and I just love eating the berries! Like carrots, strawberries were a crop that I always wished we had our own year supply of and now that wish has come true. If you want to see everything it takes to start and maintain a June bearing strawberry patch all in one place, you can find a very detailed post on the subject in our online Classroom. Just type “strawberries” in the Classroom search bar and it will pop right up for you. I will be available in there to answer questions if you have any.
Lesson #2 - LED vs T5 Grow Lights
When searching for comparisons between LED and T5 grow lights on the internet, you quickly encounter a lot of misinformation. Half of the sources can’t share anything specific and the other half are trying to sell you something. Therefore, it is a challenge to discern the truth. I am a numbers guy so when it came to figuring out which grow lights were actually the best for our seed starting process, I couldn’t help myself from going all in to collect some really good data in order to make a fair comparison. . When examining the intensity of grow lights, we are often led to compare output measured in lumens. I wish it was that easy. Unfortunately, the lumen rating of a grow light is irrelevant because lumen measurements are designed to indicate the intensity of light in the spectrum most visible to humans.
Plants use a broader spectrum of light than what is visible to humans. They are especially good at absorbing red and blue light which isn’t well accounted for in lumen readings. The best way to measure the usable light output of grow lights is with a quantum sensor that records the total amount of Photosynthetically Active Radiation (PAR), that is the amount of light that falls within the spectrum that plants can use. Therefore, for my comparison, I used a quantum sensor for all measurements.
Using this sensor, I compared 4 foot T5HO lights and 4 foot LED strip lights. They were suspended over a 20 by 44 inch rectangular grid at heights of 4, 6, and 8 inches above the quantum sensor. A light reading was taken at the centre of each square in the grid so the light intensity could be compared across the whole area. I took readings for single lights and banks of 2, 3, and 4 lights. The resulting data allowed me to determine whether LED or T5 lights were better in the long run as well as the appropriate number of lights to use per shelf and the height they should be above my plants. A summary of the results is posted in our online Classroom. Just type “LED vs T5HO” in the search bar and you’ll find it.
Lesson #1 - Taking Onion Storage to the Next Level
Some lessons present themselves to you in the garden as problems and others you just need to put in the time to figure out. Like the grow light question I addressed in Lesson 2, today’s onion lesson was one that we just needed to put in the time to figure out. We have made small adjustments to our onion storing methods each season and I have noticed that the onions we hang tend to store the best. The airflow that hanging allows really helps to keep the outer shell of the onions dry preventing decay. I have braided onions occasionally, but the braids were never as strong or tight as I would like. Cured onions can also be stored well in a hanging mesh sack or length of pantyhose, but I don’t really want either of those options hanging in my kitchen. Therefore, one of my goals this season was to figure out a method for hanging onions that was effective AND attractive. The solution was to hang the onions by fastening them around a set of centre strings as shown in the photos today. These bunches were made with Cipollini, Cabernet, and Cortland onions. I know we are not the first to string onions like this. I occasionally come across others doing something similar or old homesteading books with drawings of onions hung in this way. But since the skill of stringing onions was new to us and added so much appeal to our onion crop, I have ranked this lesson as number 1 for the season. I couldn’t be happier with the result. The onions are very secure in each bunch, they look good together, and each onion is still easy to access one at a time. There are our top 10 lesson from the 2019. I am sure 2020 has something new in store for us again so we will press on improving our production year after year. If you are ready to take your vegetable production more seriously head to our online Classroom to join our community of growers who are taking food production into their own hands.