Long and Cold Spring

What about planting tomatoes?

If you are like the educators on the Garden Hotline, you already have tomato plants in hand, waiting to set them out. OR wait, maybe you already did! It seems like it should be time but this year our spring weather has been particularly cold and wet. If you have set these heat lovers out, never fear, you can still protect them. Ideally tomatoes like a soil temperature of 60 degrees consistently. Cooler than that and they just sit there, wondering what to do. Air temps are perfect for tomato plants between 65 and 85 degrees F. So our goal is to get to more regular warm days and warm soil temps for heat crops to thrive. One way to know is to use a soil thermometer – another is to extrapolate from the weather station closest to you, monitored by WSU and accessible to you through the data shared on their website. Right now at the weather station at the Center for Urban Horticulture, where Seattle residents can get a glimpse of what might be happening in their garden, the soil temp today on May 13 is just at 57.3 F and air temp just below that at 57.1 F at 6:28 pm.. For Sultan, higher into the Cascade Mountains soil temps are at 51 F. It’s cool out there! But hang in there – there are some things you can do.

Pot your tomato plants into larger pots and grow them a little bigger for a week or two. Hopefully the weather will be more conducive to our heat crops by then. Keep them in a sunny window or if you are a lucky person with a greenhouse put them inside there.

Cloche your plants – add some flexible pipe over your beds and cover them with greenhouse grade plastic to keep them a few degrees warmer. This will suffice to keep them protected until the weather warms. You should open the ends to vent and avoid too much moisture on the leaves. Cloching can increase soil temps too.

Surround them with a mini cloche like the commercially available wall-o-waters which hold tubes of water around the plant that warms with solar radiation during the day and emits heat as the sun goes down to keep the air warmer around the plants day and night. Or try a homemade version with bubble wrap around tomato cages. This is not quite as effective but does help.

Go ahead and start hardening them off and don’t worry about planting yet – put them out in the day and bring them in at night so they get used to outdoor temperatures and light. Avoid putting them in hot bright spaces until they are tougher and their leaves are thickened up or they will sunburn. Hardening off can take a week or so.

It’s ok, some folks don’t set their tomato plants out until June and get good crops. We have time, especially if you have short harvest window varieties from 75 days or less. And remember tomatoes have friends that feel the same way they do about cold and wet springs. Treat them the same as your would your beloved tomato plant. Peppers, eggplant, tomatillo, ground cherry, basil, cucumber, beans are some of the types of veggies you should coddle right now. All of these are a bit cold shy.

Call us if you want tomato therapy talk time. 206-633-0224