Planting Perennials: Tips for Happy Plants

by Sep 2, 2025Education

While you may already be familiar with the basics of planting, I’ve picked up a few helpful tips from fellow plant enthusiasts over the years that have made a big difference in my success with transplants. 

Tip #1: Plant in the fall. As we head into the cooler, shorter days of September and October, planting might be the last thing on your mind. However, it’s the best time to plant in Flagstaff.

The milder temperatures are much less stressful on plants than the dry heat of June and July, the cooler days means the soil stays moist for longer, and the best part? You plants will have all winter to settle their roots in for next year. 

Tip #2: Dress up the planting hole. Time to get fancy! The first part of dressing up the hole is to add a handful of compost into the hole and mix it into the soil at the bottom. This gives the new plant a little nutrient boost.

The second part is to pour water directly into the hole before you plant. This technique, which I learned from Gina, our Greenhouse Manager, really helps ensure that the roots get a good drink from the start and encourages them to grow deeper into the soil. I always water the plant in after it’s been planted, too, but the extra water in the hole is an excellent arid gardening tip!

Tip #3: Cover the potting soil with your garden’s soil. I love this tip! I add it here because the potting soil the plants come in when you buy them from the nursery always dries out so fast. So as I’m tucking the new plant into the ground, I scrape off about 1” from the top of the potting soil. Then, as I keep adding dirt around the plant, I end up having the dirt covering the potting soil, and my plants don’t dry out so quickly.

Tip #4: Keep your plants watered for the first year or two. Now, you have probably heard this tip over and over again. But it is worth mentioning yet again, especially if you want plants that give you delight for years to come. Basically, as with all these tips, the goal is to minimize stressing the plants out for the first year or two. Thus, with new transplants you don’t want to keep them constantly wet like a bog, but you also don’t want them to get dry like a desert. Instead, keep an eye on your plants and make sure the soil is moist for the first 3-4 weeks, say all of September, and then in October until the snow comes, water them when the soil is just starting to dry out.

With these handy tips, your garden will soon be filled with healthy, well-rooted perennials ready to bloom year after year. Just be patient as your plants go through their first three years – “Sleep in year 1, creep in year 2, leap in year 3.”

Sarah Armanovs is the Gardens Manager at The Arboretum at Flagstaff.

Sarah Armanovs