Many of the vegetable crops that we grow don't necessarily need to occupy the gardens for the
entire growing season, especially with the extended growing season within the
polytunnel. And there can often be benefits of trying to fit in another crop, either before or
after the main one. And some crops only really produce well for a short period of the season,
including high value crops like climbing beans, and it's good to be able to sow several different
batches at different times, in order to extend or stretch out the harvest period. I also like taking
advantage of the protected growing space of the polytunnel in order to extend the growing season,
to get potentially an earlier harvest and even a later harvest out of crops that were commonly
grown outside, such as courgettes or zucchini. And I've been thinking about possible pairings
of crops that could work quite well in combination like this. So this past year I decided to explore
a succession option like this in a bed in one of my polytunnels, where I grew a series of batches
of climbing beans in order to get a more continual supply over a longer period of the season,
with courgette or zucchini plants planted either before or after the bean plants.
The main focus of this planting was to try to get a continual supply of beans over a really long
part of the growing season, and I found that climbing beans, or what we often call French
beans, can produce really well in the polytunnel. I have found that bean plants like this will
generally produce a really good yield for the first four weeks. They can produce for longer
but the quality tends not to be as good, and it can be a bit delayed, and diseases can often set
into the plants, so I thought it'd be useful to focus mainly on that 4-week flush or cropping
period. So this year I thought I would grow four different plantings, sown about four weeks apart,
which would theoretically produce a harvest season of about 16 weeks, if the timing worked out,
but the later plantings could be left in the ground for producing longer. And this would
set up the main structure of timing for the plantings of the four sections of the one bed
that I would have to work the courgette plants around. I figured there was enough time to get
two batches of early courgette plants to produce reasonably well, before they need to be pulled
out so that the later two batches of bean plants could be transplanted into those sections of the
bed. And when the first two batches of bean plants were finished their main harvest I wanted to have
courgette plants ready to transplant into those sections of the bed, in order to be able to have
good quality courgettes late in the season. This would theoretically allow us to harvest a lot of
courgettes both early in the season and later in the season, which would extend the normal cropping
period that we get in the main crop of courgettes in the outside gardens. And with this schedule,
parts of the bed would be empty for a while at the beginning of the season,
so I decided to grow a fast growing green manure to fill in this space. This meant that there
was three different types of crop or plantings intermixed in the same bed in the same season,
with the possibility of a fourth overwintering crop to be added at the end of the season.
This is all relatively simple, with two batches of early beans that are replaced by courgettes
later in the season, and two batches of early courgettes that are replaced by beans later in
the season. And the timing of all of this was structured around the sowing of beans
every 4 weeks. And I decided to grow two different varieties of beans in each batch,
a long pencil type and a flat Romano type, both of which had done really well in the
variety trials last year. I felt that the early crop of beans probably needed more time to grow
in the cool weather, so I sowed this first batch a week earlier, on the 24th of March,
which was the earliest I've ever sown beans like this, and some of the young plants were damaged
when the frost got into the polytunnel later in the spring. I felt that the timing for the sowing
of the first two batches was quite good, both of which were planted into the poly tunnel 2 to
3 weeks later. But when it came time to sow the third batch the courgette plants that they were
supposed to replace were only just starting to produce, so I decided to delay the planting a bit,
and then got distracted. So I ended up with about a six week gap between the second and third sowing
of beans, and I thought that this would lead to a gap in harvest later in the summer. And
I sowed the last batch only 3 weeks later, as I felt that there might not be enough time in the
season for them to produce anything. So the timing between the batches of beans was first 5 weeks,
then 6 weeks, then 3 weeks, which was not what I had planned, but it ended up being close enough.
With the early batches of courgettes it was a little bit more difficult to figure out the
timing, as I wanted to sow them early enough so that I could get a good harvest, before the
plants needed to be removed and replaced by the beans, but not too early, as they wouldn't grow
well in the cool weather and there was increased risk of frost. And the plants might grow too big
for the space before the bean plants were ready to replace them. I sowed the first batch at the
beginning of March, and transplanted them into the bed four weeks later, at the same time as I
sowed the second batch. I sowed the third batch of courgettes when I started harvesting the
beans from the plants that they would eventually replace, allowing four weeks of harvest to match,
more or less, to 4 weeks of the courgette plants growing in the pots. But I ended up leaving these
courgette plants in the pots for 10 days longer than I had planned, as the beans were producing
well, and I didn't want to interrupt the harvest. So these courgette plants were quite stressed by
the time I transplanted them into the ground. The fourth batch of courgettes was delayed as I was
away from the gardens for a few weeks, and then struggled to catch up with tasks when I returned.
So I didn't end up sowing it until the beginning of August, which is really late, about a month
after it originally planned. This worked well for getting more beans off of the plants that they
would eventually replace, but it really impacted the crop of courgettes later in the season.
We started harvesting beans off of the first batch at the beginning of June, and it was great to get
such an early crop, though there wasn't a lot of them for the first 3 weeks. I think these
plants had struggled with the competition from the green manure that I had left growing beside them,
and they also had to recover from the frost damage. I'll know better next time to give
these plants extra care, and to protect them from the frost, and to make sure that they didn't have
to deal with any extra competition. Leaving these plants in the ground for longer and delaying the
planting of the third batch of courgettes did help produce a good overall yield from these plants.
The second batch of beans produced really well over a 6 we period, and had really big harvest
for two of those weeks. I'm not sure why this was so much better than the other batches. It could be
the timing of the crop in the middle of the summer but the plants also seemed bushier or more full,
even though there was the same three plants per station or twine as with the other batches. The
delay in sowing the last batch of courgettes allowed these beans to stay in the ground for
longer which really boosted the overall yield, and the harvest only started to slow down when there
was time to remove them. This extended harvest of the second batch of beans meant that there
wasn't the gap in harvest that I anticipated when I delayed sowing the third batch of beans. This
third batch cropped reasonably well for the first four weeks, and because I could leave them in the
ground for longer, as I didn't have any plans to replace them, they continued to produce a
reasonable quantity and quality of beans for another six weeks in the Autumn. The fourth
batch did produce fewer beans than the other batches, but they did help end the season,
and it is interesting to see how much less they produce than the plants that were sown
3 weeks earlier. which shows the importance of timing with late season crops like this.
The first batch of courgettes produced really well, with harvest starting at the beginning of
May from all three varieties that I had sown. The fleece and the thermal mass seemed to really help,
though I'm not sure that they were overly affected by the green manure in the same bed,
but it probably would have been better to reduce any impact. In hindsight I probably didn't need
to delay sowing the beans that would eventually replace this first batch of courgettes especially
with the second batch of courgettes starting to produced shortly after. This second batch was
useful to help fill the gap before the outside courgette plants started to produce, and there
was about a two week overlap. So I probably could have pulled out the second batch of courgettes,
and got the last batch of beans transplanted in a few weeks earlier, which probably would
have increased the harvest of beans later in the season. And these earlier courgette plants ended
up growing really big and overcrowding the space, so it would have been okay to remove them earlier,
if I didn't want to prune or train them. I did prune the autumn batches of courgettes,
removing the older leaves and any side shoots that developed, and took the time to tie them
up to a cane to allow them to grow vertically. I was more concerned about ventilation and diseases
with these plants later in the season, and I successfully use milk spray to reduce the
impact of downy mildew. So I took better care of these plants, once they were in the ground,
though the first batch of plants would have been set back from being in the pots for too long. But
they ended up producing a reasonable yield later in the season, which was quite welcome
especially as the outside plants were starting to really slow down. The amount that we were
able to harvest each week from these plants seemed to really be affected by the weather,
with considerably less available to harvest during the cool period in September. The fourth batch I
simply sowed too late, and I was only able to get a few usable courgettes from these plants,
and I would have needed to have sown them at least a few weeks earlier to get a worthwhile crop.
Overall we were able to harvest beans for more than 20 weeks off of these four batches,
with 16 weeks of good quality beans and decent size harvests, which was great. There were a few
weeks with really big harvests, which is a great time for preserving beans,
and lots of weeks with really good harvests of good quality beans. And at the scale that I'm
growing at there was lots to share with friends and neighbours over a long season. I haven't yet
pulled out the plants from the last two batches, and they're still producing into early November,
but the growth is slow and the harvest won't be big, and not as good a quality
as during the summer, but any fresh harvest is appreciated this late in the season. The
crops of beans were really good in this succession pairing, the one issue was
that the young plants were generally too big and root bound by the time I got them transplanted,
but I'm not sure what kind of impact this would have had. I also snapped the growing tip off of
a few of the larger plants while transplanting, which would have changed how the plants grew,
focusing more on the side shoots rather than the main leader for the early part of the season. I
wonder if this contributed in a delay in the pods developing, or produced bushier plants in
some situations, which might have had the result of producing bigger harvests for a longer period
of time. This may have had an impact on the yield and the pattern of harvest between the batches,
possibly for the better, and this is something that I want to explore some more in the future.
I was quite happy with the big yields that we got from the courgette plants earlier in the season,
with good quality courgettes available for harvesting for more than 6 weeks before
the plants outside started to produce. But the yield later in the season was definitely lower,
and I'm not sure if it was worth the effort of growing and caring for these plants. Pollination
was also an issue with the large courgette flowers, especially later in the season when
there was very few pollinators anywhere in the gardens. But thankfully the bean flowers don't
need pollination. And the plants seemed to produce very few male flowers for periods
both in the Spring and the Autumn, and I don't really know why, but this meant that
hand pollination wasn't really an option for these times. And all of this led to quite a few
aborted fruit at times which would have reduced the possible yield especially in the Autumn.
We were able to harvest more than 90 kg of beans from the four batches in this one long bed,
which is a huge amount of beans. And we were able to harvest about the same weight of courgettes,
mostly in the spring when they were more valuable. This is a total of more than 185 kg of high value
vegetables harvested from one bed of this poly tunnel, which translates to more than 12 kg per
square meter, or about 10 kg per linear meter, which is a good yield. I suspect that cropping
could be improved a bit with better care of the young plants, especially transplanting them into
the ground before they got too big, and making sure that there was no competition from the green
manure. The Autumn crop of courgettes would be improved quite a bit by sowing and transplanting
them earlier in the summer, but this would reduce the potential harvest of beans. And I'm wondering
if the two Autumn batches of courgettes are even worth, it especially that the Autumn courgettes
are not nearly as desirable or valuable, as the early courgette harvests in the spring.
And with the pollination issues, and the need to put in the work to prevent downy mildew,
it might be better to simply let the beans produce for longer, and eventually replace
them with a more appropriate cooler season crop, rather than the courgettes. Another potential
option would be to grow three batches of beans and courgettes in a season, rather than four,
which would reduce the pressure of timing, and prevent the need for pulling out plants when
they're still producing well. And it might be better to diversify the pairing or succession
crops, to select a different crop both before and after each batch of beans, selected for the
season and the amount of time that's available for growth. An early crop of courgettes could
still work really well as part of one succession pairing, but I'm no longer convinced that this
warm season crop works well as a pairing with each batch of beans especially later in the season
One of the things that I really like about this RED Gardens Project is the ability
to try something or test something out, at a significant scale. I have a community that I
can easily distribute surplus crops to when things grow really well, and when there's a failure or
when things don't grow nearly as well as I had expected, there are lots of valuable lessons and
learnings that are useful for me, and that I can share through videos like this. If you like this
type of exploration, and get something useful out of these videos, and have the spare resources,
please consider supporting my work and this YouTube channel, through either Patreon or PayPal,
the links to both are in the video description. And thanks to everyone who has already supported
this project over the years, this video would not exist without this support. And thanks for liking,
sharing, subscribing, and commenting, but more importantly thank you for watching!