It's the start of summer, so it's all about giving a feeling of coolness (涼一味、りょういちみ）. Ideas:

• Indigo
• Silver kettle
• Wetted びぜん ceramics (for example, for 花入)
• Or a boat as a 花入
• Use smaller 釜, so you can see the ash form
• つるべ as 水指, or one with a wide mouth
• An insect-related 香合
• Crab for 蓋置
• Flat 茶碗
• Generally, glass items for food, like Baccarat
• And fresh wood, in general
• White and blue chinaware for 懐石
• Salt-あゆ are good for 焼物; maybe summer-duck for にもの or roasted duck for 八寸. Shrimp for むこ付け or fried for 八寸; and of course, aubergine for all (でんがく, てんぷら, pickled with mustard; cucumbers

• Mittwer : Lady's slipper, thistle, and loosestrife

• Sen says wild lily