Feed the heavy hitters, soak deep, brace for Sunday's 98°F slap.
Side dressing tomatoes Portland June is the chore I'm doing this Wednesday afternoon, before Sunday's forecasted 98°F slap rolls into the Eastside. My corn is knee high, the indeterminate tomatoes are setting their first trusses, and the squash is about to vine out — all three are about to get hungry fast. If you feed them now and water deep before the heat lands, you'll coast through the spike instead of watching leaves curl.
This Week's Action List
- Side dress tomatoes once the first fruits are the size of a quarter: scratch in about a tablespoon of blood meal or 2 tablespoons of a balanced 5—5—5 per plant, six inches out from the stem, then water it in. I skip high nitrogen feeds (anything with a first number above 7) on tomatoes because I'd rather have fruit than a six foot leaf bush.
- Corn is the nitrogen hog of the patch. When stalks hit knee high — right about now in most Portland gardens — band a half cup of feather meal or composted chicken manure down each row, four inches off the base, then mulch and water in. I'll hit them again when tassels show.
- Before Sunday's 98°F day, give every warm season bed a long slow soak Friday evening or Saturday at dawn. I run drip lines for 90 minutes on tomatoes and squash to push water down 8 to 10 inches; shallow watering during a heat dome cooks roots and invites blossom end rot.
- Sow your second succession of bush beans this week while soil is in the mid 60s°F — Provider and Jade are my reliable Portland picks. Get them in by Thursday so they germinate before the Sunday scorch; cover the row with burlap or shade cloth if the heat lands before they sprout.
- Pick lettuce hard right now. With Saturday at 85°F and Sunday near 98°F, every head of Buttercrunch, Salanova, or Jericho left in the ground will bolt by Tuesday. I harvest whole heads at dawn Friday, wash, spin, and stash them in the crisper — that's a week of salads saved from the heat.
Frequently Asked Questions
How often should I side dress tomatoes in Portland?
I side dress twice per season in Zone 8b: once when the first fruits reach quarter size (usually mid to late June) and again when the plants are in full harvest in late July. Use a balanced or low nitrogen feed like 3—4—4 or 5—10—10 — too much nitrogen after flowering gives you jungle foliage and weak fruit set.
Should I water my vegetable garden before a Portland heat wave?
Yes, and water deeply the evening before or the dawn of the hot day, not during peak heat. A long soak that wets the top 8 to 10 inches of soil acts as a buffer; plants pull from that reservoir while their stomata close midday. Mulch two to three inches deep with straw or fine bark to hold that moisture in.