Anyone who gardens in the Pacific Northwest comes to realize that while it is a great place for growing a wide variety of plants, heat lovers aren't among them. Tomatoes will do okay without too much extra care, although their flavor will pale compared to those grown in a midwest garden. Summer squash do well once summer (such as it is) finally hits. Winter squash will do okay IF the summer is decent and IF reasonably early varieties are grown. But the secret of getting melons to grow well and ripen eludes many, if not most, maritime gardeners.
I don't have a magical formula that will turn your melon patch into an overflowing source of sugary goodness - we just don't have the weather for it. But I can give you a few pointers that might help you to coax some truly ripe, tasty melons out of your cool northwest garden.
Choose Early Varieties
If you read through the canteloupe and watermelon offerings of various seed catalogs you'll find a wide range of times to maturity listed. If you haven't had success with melons in the past, you should rely on the earliest offerings from Territorial Seed Company or Johnny's Selected Seeds.
Once you've got a couple successful melon-growing seasons under your belt then you'll be better able to judge what will work in your microclimate - but you'll probably still do best sticking with the varieties sold by these companies.
Unless you live at the far south end of our territory, there's just not a long enough period of warm weather for direct-seeding canteloupe or watermelon. This means you have to start your melons indoors. In my Sumner, Washington location I sow my melon seeds into four-inch pots between the 10th and 15th of May. Melons are not as vigorous as squash, so this size pot will be good for three or four weeks.
Using a heat mat will greatly increase the speed of germination as well as the number of seedlings that come up.
Thin to One Plant per Pot
This might go against the grain, and it's certainly counter to common advice. But over several years I've found that in my garden, I get as much fruit from one plant as I do if I leave two to compete for light and nutrients. My thought is this allows one plant full access to the water and nutrients without competition. Since we're trying to grow these plants in a region that barely will support them at all, any advantage we can provide is worth taking.
Melons are very touchy about root damage! So do not pull out extra seedlings. Instead, thin out the unwanted plants with scissors. NEVER try to separate out the extras - you'll probably severely damage or kill your plants.
Transplant carefully, and feed them well
Water your seedlings the day before moving them into the garden. For each planting spot, work one cup or so of complete organic fertilizer into the soil. Then invert the pots and CAREFULLY remove the plants from the pots.
Set the plants about three feet apart in raised beds.
Modify their climate
Melons simply won't grow well here out in the open. Please believe me; I've tried. This is one crop that really needs a low cloche - temperatures under a PVC hoophouse simply won't be high enough for optimal canteloupe and watermelon growth.
I generally don't uncover them unless the temperature is quite warm. Some summers that means they never see the sun except through the plastic! You do want to vent the ends of the cloche to help prevent disease; but it's almost impossible to overheat these plants.
I've always used black plastic mulch on my melon beds, but infrared-absorbing mulch (like IRT-76) will warm the soil better and so probably is a better idea. I plan to do a comparison this year in my garden's melon patch.
Thin the excess fruit
It's always hard to remove the baby fruit, but anything that's not reasonably big (say baseball size) by mid-August will probably not ripen - they're just going to be removing nutrients that otherwise could go to the larger fruit. So consider removing any small fruit and flowers after this date.
Melons need a reasonable amount of water during their main growing season, and will do fine with the same level of irrigation you give the rest of your garden. Once the fruit are sizing up, though, it's a good idea to cut the water by at least half. This prevents fruit splitting and also concentrates the flavor.
Canteloupe are generally ripe at "half slip". That means when you can separate the melon from the stem with a little force. A few varieties have different rules for ripeness, so be sure to read what the seed catalog has to say.
Watermelon ripeness is a bit trickier. I like to wait until the tendril nearest to the melon's stem has died. Others prefer to "thump and listen". If in doubt, leave it on the vine a bit longer.
Don't have unreasonably high expectations
Following the steps above, I can pretty much count on getting at least a few canteloupe even in a poor summer. In a good summer I might get a dozen or so ripe fruit off three or four plants. But I'm lucky if I get a ripe watermelon half the time - that's a pretty low success rate! But when I do get one (I think three in one season is the most I've ever harvested) I feel pretty good about it.
All contents © Travis Saling
This page was last updated November 18, 2013