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Flower Forecasting

It doesn't take long after planting for our kids to start asking "When do we get to pick [insert tasty crop here]?" I can usually give them a pretty accurate answer because I've been keeping planting and harvest records of everything we've grown for the last decade, but if you don't have those records yet, there is an alternative place you can find this information and it's right in your garden. You can actually use the flowers of many crops to accurately forecast the start of their harvest periods. I'm going to take some time this month to show you a few examples of flower forecasting so you can try putting it into practice in your own garden.

Potato flowers give us information about the state of tuber formation underground.

The basic idea of flower forecasting is simple. Many of our vegetable crops make flowers before creating the more desirable product that we harvest to eat, and the length of time between the first flower and first harvest is measurable, consistent, and therefore predictable. Sure, when you survey a garden quickly, the assortment of flowers and distribution of harvestable foods might seem quite chaotic, but when you take time to note the patterns that chaos turns to order. In this case, that order lies in the number of days between the flowering and harvest. This period of time is different for each crop, but it is consistent, so if we know the length of this time delay, we can accurately predict the start of our harvest periods. Let's look at a few examples.


The first crop to flower this spring was our June bearing strawberries. Judging by their name, you'd think that they would bear the majority of their fruit in June, but in our region the harvest period is actually in early July. I love my berries so I'm always extra excited for any developments in the strawberry patch. This one requires some patience though, because once I notice flowers developing in early spring, I still need to wait 30 days until I can pick a mature strawberry!

Snap Peas

Another early spring crop is our sugar snap peas. They have a DTM rating of 62-70 days, indicating that I should be able to expect our first harvest 62-70 days after seeding. The DTM ratings can often give you a pretty close prediction, but seasonal changes in weather and transplanting actions can impact this timing. A more accurate indicator is the timing of the flowering, because it's a clear visual sign that the pea pod production is about to start. I have a few photos of the first pea flowers dated for Jun19th this season, and our first few snap peas were ready like clockwork on June 29th. That's because it always takes 10 days for our snap peas to go from flowering to full maturity.


Another crop flowering right now is our cucumbers. Just as with our snap peas, we transplanted our cucumbers, then the plants started flowing a while ago, and we had our first harvest this week. However, the timing of every stage was entirely different because the cucumbers are running their cucumber program, not the snap pea program. According to the cucumber program, fruit is ready for harvest 7 days after flowering. It's amazing to see such large fruit appear so quickly. It's almost hard to believe, but it's consistent. In fact, as a market gardener, I depended on this flower forecasting every year to anticipate the first big cucumber harvest I would have ready for my farm members.


Another eagerly awaited crop is tomatoes. This is one that requires some patience though. The first flowers can often be observed shortly after transplanting, but that doesn't mean we'll be eating fresh tomatoes the next week. We can expect to wait at least 40 days for our first fruit to form after this point.

By this point, you probably get the idea. If a crop flowers before producing a harvest, it does so with consistent timing. If we know this timing, we can accurately predict any major harvesting tasks in our garden and this knowledge helps us better plan our summer, or at least confidently tell our kids that they only have to wait 2 more weeks before they get to start harvesting strawberries. The only challenge to this trick is that the length of time from flower to harvest for each crop is unique. I can't make that any simpler for you, but I can organize the flower-to-harvest timing for 12 of our common crops and present that information on one simple chart. Here you go...

I should add a couple of clarifying notes about the chart above.

  • The timing for "New Potatoes" should be considered the absolute earliest time to rob your plants of any newly formed spuds. The quality of this tender new potatoes will be outstanding but the yield will be very low. I think it's worth leaving most potato plants in the ground until they have fully matured (ie. the potato vines have died back) so that you can achieve a much higher yield from your growing efforts.

  • The melon average is 50 days. Muskmelons are a few days faster and larger watermelons are few days slower.

  • Peppers can mature in size a sooner than 60 days, but they often require more time to ripen up to their final colour.

  • Winter squash has some variance from one variety to another, but 60 days is a fair estimate to begin with.

Okay. That's all for this one. Have fun predicting your future harvests! Once you're confident with this concept, your next challenge is predicting the end of harvest for each of your crops. That's information you'll never see on a seed package but it's so critical for planning when to start the crops that are coming after your peas, or after your beans, or after your melons. I cover the subject of harvest patterns in detail in Module 6 of the Seed to Table course, so you can meet me there to take things to the next level.


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