Spring is almost here and it’s time to start thinking about all the delicious vegetables and beautiful summer flowers we want to see in our gardens. Dreaming is the easy part, but as any seasoned Flagstaff gardener knows, reality often takes a harsh toll on our tomatoes. For the gardeners new to this area, it is important to know that the “frost free” window is more of a concept than a concrete time frame. The truth is, it can freeze at any time of the year in Flagstaff. Generally speaking, we consider the frost-free gardening season to be June 15th to September 15th. That is usually, emphasis on usually, the time when it is safe to plant tender garden starts without worrying about them freezing overnight. That being said, it is wise to plan for protection and spring is the perfect time to acquire all the supplies needed for a successful summer garden. Below are a few tips to help you get started.
Frost Protection
If you’re planning to get a jumpstart on the garden in early June or if you see the inevitable late June freeze coming, walls of water and/or frost cloth is a great option. This enables the gardener to temporarily protect the plants from intermittent cold nights. Remember, these will give you a few degrees of protection- if it is a deep freeze, you will need to take more drastic efforts. At the Arboretum, we average 10 degrees colder than in town, making our “frost-free” nights limited in supply. Two years ago, we had a deep freeze at the end of June. Even with frost cloth, it decimated our newly planted vegetable garden. This year, with help from the City of Flagstaffs Sustainability Grant Program, we will be installing locally-owned Steady Harvest’s mini-tunnel raised bed coverings on two out of the four vegetable garden beds. With the harsh weather we experience year-round (I haven’t even mentioned hail in this article) these more permanent, durable structures will help us get through all the weather mother nature has planned for us this season. If you are interested in adding these tunnels to your garden, visit Steady Harvests website and stay tuned for an upcoming workshop at the Arb where you can see how these mini tunnels are built!
Sun Protection
Not only do Flagstaff gardeners have to worry about overnight freezing, but our intense high elevation sun can be harsh on newly planted gardens too. Shade cloth is a good option for intense mid-day sun exposure on tender plants, but it requires you to be at the garden to put on and remove throughout the day making it often impractical. Mulching is perhaps the most vital sun protection we can offer to our gardens. Applying a few inches of mulch across the surface of our garden soils helps retain moisture and cool the soil down, keeping our plant roots happy and healthy. Be sure to keep the mulch away from the plant stems (just an inch or two) to maintain air flow.
Watering
It is vital to have a hassle-free way to water your garden. If you are battling your hose every morning, you won’t want to do it. And yet, the window after planting and before the monsoon season kicks off, almost daily watering will be necessary (depending on location and mulch). Consider installing an irrigation system to help ease garden maintenance. While it can be a pain to establish, it is the most efficient way to keep your garden watered in the hot and dry months.
Plant Varieties
What you plant matters! When seeking out flower and vegetable varieties, look for short season maturation. Our growing season is 90 days, and due to our cold evenings that delay growth further, it’s safe to add at least 14 days to the timeframe on the seed packet. Some of my favorite vegetable and flower seed sources for the mountain west are Grand Prismatic Seed and High Desert Seed.
Companion Planting
Utilizing companion planting helps deter pests and prevent disease, aid in sun protection, attract beneficial insects and improve overall plant health. Simply put, encouraging these symbiotic relationships helps keep all the plants in the garden happy. One of the best relationships is tomatoes and basil. Not only are they delicious together, but the basil repels common tomato pests like thrips and aphids. There are too many companion relationships to list here, for more information, check out the Farmers Almanac Companion Planting Guide.
Timing
While the vegetable growing season is June through September, remember that monsoon season through Fall is the optimal time to plant trees, shrubs, and perennials. However, the Spring fever is real and we get it. Our retail nursery will be open May 1st with a variety of perennials and with the appropriate amount of care, you can enable these plants to thrive. Just remember the recommendations listed above and apply as necessary.
Gina Goegan is the Greenhouse Manager at The Arboretum
