June Portland Garden: Late Blight Watch and Fall Brassicas

Late blight patrol, fall brassica seed trays, drip lines on the clock, roses in full showoff mode.

The first week of June is the pivot point in the Portland Zone 8b June garden: warm season crops are settling in, roses are hitting peak bloom, and the dry season is here even if the sky hasn't fully committed yet. Fall planning starts now, not in August, because brassicas need eight to ten weeks indoors before their late July transplant window. This week is about setting the systems that carry you through August: irrigation, disease scouting, and the first fall seed trays.

This Week's Action List

Frequently Asked Questions

When should I start fall broccoli and cabbage seeds in Portland?

Start fall brassica seeds indoors in early to mid June for transplanting out in late July. That gives seedlings six to eight weeks under lights and lets them mature into the cooler September and October weather, which is when brassicas actually taste their best in Zone 8b.

How do I know if my Portland tomatoes have late blight?

Late blight starts as irregular dark green or brown water soaked spots on leaves, often with a pale halo, and it moves fast during humid or damp weather. Within days you'll see white fuzzy growth on leaf undersides and stem lesions. Any tomato showing these signs needs to come out whole in a sealed bag, not composted, because spores travel by wind and rain to every solanaceous plant nearby.

How much water do Portland tomatoes need in June?

Established tomatoes need consistent deep watering every two to three days in June, roughly one to two gallons per plant per session depending on soil and mulch. Inconsistent watering causes blossom end rot and cracked fruit, and overhead sprinklers invite blight. Drip or soaker hose at soil level in early morning is the right delivery.

Is it too late to prune my rhododendron in June?

Early June is your last clean window. Rhododendrons and other spring bloomers set next year's flower buds in late June, so cuts after roughly June 25 remove next spring's flowers. If you missed the post bloom window in May, prune this week and stop by month's end.