Summer Tips: What to do in Your Seattle Garden for June

Image via Wikimedia

It’s a busy time in the garden! Things are growing and flourishing this month. This dynamic time means you need to be active in shaping what grows and where. Too much growth can actually be a bad thing, so it’s up to you to be strategic and shape your garden into what you truly want. 


You can continue planting warm-weather vegetables that will give you a great harvest in the fall. The doors are wide open to plant most things: cucumbers, melons, root veggies, corn, greens and onions are all on the table. Just don’t wait too long. You need to get most of these in the ground shortly to ensure they’ll be ready to harvest in a few months. Check out ‘Growing Vegetables on the West Side of the Cascades’ a great book which helps choose the best plants for our short growing season.

You can also plant more flowers, such as dahlias, petunias, asters, gladioli and marigolds. Make sure to water new plants deeply, but not too frequently. This fosters better root growth.


As vines and other skinny plants begin to take off, you may want to direct them upwards onto a trellis. This helps support the plant and also guides it upwards so it takes up less space

Trellises may be pricey but you can build your own. This can range from something as simple as two stakes in the ground with wire between them, to a wooden frame with slats nestled into it. Whatever you do, just make sure that your support poles are sunk securely and deep enough to support the weight of the plant-laden trellis. One rule of thumb is to make sure one-third of the total post height is underground.

Once you have your trellis up, you need to train your plants to stick to it. Some vines will intertwine themselves with the trellis naturally, others you will need to wrap through the trellis and fasten with twine. Trim vines headed in the wrong direction to help keep the main ones on track.

Not only do trellises offer benefits to plants, they can offer a huge design upgrade to your garden by serving as screens for seating areas or cutting down the visibility of your neighbors’ homes. If you want to learn more about having custom trellises built and installed, give us a call at 206-551-9872.


As plants begin to pop up, make sure to thin them out. Remove extra growths to ensure that the plants that you want to grow get sufficient sun and nutrients without being weakened by adjacent competitors. Ensure the healthiest seedlings have one or two inches of space around them. Thin earlier than later to avoid accidentally damaging plants.

Some plants should be pulled out, while others can be trimmed at the base with scissors or other fine-cutting tools. When in doubt, consult seed packets for optimal spacing information.


Make sure to keep up with other trimmings. Now is a good time to remove blossoms from rhododendrons, lilacs and other spring blooms. Remember to only remove the blossom and leave the rest of the foliage intact. Also, keep up with mulching trees and shrubs to suppress weeds and ensure plants have plenty of nutrients.

As the season goes on, some perennials may begin to get longer and scraggly. Fix this by cutting back a third of the leggy stems in the front of the plant. Known as “pinching,” this encourages density in the plant and can renew its crop of flowers.

If lettuce “bolts,” meaning it tries to shift into leaf production, it’s too bitter to eat and can be removed. You can tell lettuce is bolting when the center begins to elongate into a stalk and the leaves toughen. You can delay this from happening by keeping lettuce well irrigated and shaded, but once it’s started you have a few options: you can remove it to open up space in the garden, allow it to flower to collect seeds, or cut it back in hopes of regrowth.