The question of when to begin the garden season is dependent on your level of risk taking. There are those of us who like to push it a bit to see if we can judge better than Punxsutawney Phil when spring is here, while others prefer to wait until the average last frost is past.
Here in Juneau, that magical date is the second weekend in May. It is no coincidence that gardening clubs, community gardens and commercial business participate in the annual plant sale in the Safeway parking lot the Saturday before Mother’s Day.
If your garden soil is prepped and you’ve mapped out your garden, is there harm in starting early if it seems like spring is really here? Yes and no. Ideally, plants need a certain soil temperature to begin to germinate. If it is too cold, this process won’t occur. Depending on the conditions, the seed could deteriorate and make it less viable when conditions trigger germination.
Optimum air temperatures also play a crucial part. If it is too cold, the plant might halt its growth until warmer temperatures appear, or they might not fully recover. A few years back, when we had that nice warm stretch for weeks, I finally gave in and put my zucchini starts in the ground. Of course it turned cold and the plants shrunk down. Although the temperature did warm up the plants never fully recovered. They ended up being stunted with very few harvestable zucchini.
You will not be surprised that the plants that like the colder temperatures are the ones that do well in Juneau and are best to plant early. These plants include leafy greens such as lettuce, spinach, arugula and kale. In fact, these plants react to both light and temperature.
This sensitivity means that as our days increase, those plants will opt to grow a seed stem making the leaves bitter and decrease production dramatically. Look for a soil temperature around 40 degrees and outdoor temperature of around 45 degrees. You can use a spun poly weave to cover the plants at night if the temperature drops.
For other plants, wait until after Mother’s Day to protect them, even when it seems that spring is really here. When consistent warmer weather arrives, raise soil temperatures to 50 degrees and create an air temperature that remains in the 55-60 degree range. This even applies to those vegetables that will germinate at lower temperatures like peas, cabbage, Swiss chard and the root vegetables.
When the sun is out and the air feels warm, it is hard not to want to push the season forward. That is why, at the end of February, despite my zucchini disaster I was already planting containers on the back deck of my boat.
Although the growth slowed as the temperature dropped, the lettuce, spinach and kale are doing well now. Even my broccoli that didn’t mature made it through the winter and is ready to harvest.
Sometimes the outcomes are worth the risk.
• Corinne Conlon is a freelance writer based out of Juneau. She can be reached at dirtgirlgardening@gmail.com.
