Progression picture showing a garden right after it was planted and 3 years later, with mature full plants

Is late summer the new spring for planting?

We all love spring gardening. After the months of chilly air, short days, snow-covered ground, and perhaps a dash of the winter blues we crave that time when we can don our garden gloves and get back outside as things begin to thaw and invigorate around us. It’s glorious to plant in the spring – the optimism and joie de vivre is simply palpable while tucking baby plants in the ground trusting in their future blooming potential! But wait! Have you tried planting in the late summer? We’re not about to rock the boat entirely and say late summer is the new spring for planting perennial gardens but we can all agree it’s certainly the unsung hero of the gardening seasons! Whether it’s dividing and transplanting your mature plants and building out a new garden bed with new transplants, we say give late summer a chance!


Here are our favorite reasons for planting perennials in the late summer:

  • Warm soil temperatures mean rapid root growth. Coming off of the summer months your soil will be nice and warm to help develop strong root growth. Just be sure to allow 6 weeks before the first frost (which will cease all new root growth until spring).
  • Milder air temperatures mean less transplant shock, evapotranspiration during watering, and a more pleasant climate for us gardeners too!
  • Short, bright days allow plants to transition easily into their new landscapes.
  • Jump start on spring. With the root establishment phase followed by a winter dormancy (instead of the intensity of long, hot summer days), we’ve found late summer gardens to respond quickly in spring and start above-ground growth sooner after transplant date than spring plantings. Colorado summers can wreak havoc on newly planted perennials and demand a bit more attentiveness.

The header photo shows our Resource Central office garden’s progress over the course of 9 months. Image one shows the garden upon planting in late September (year 1) and then image 2 depicts the garden in late June the following year (year 2). Quite a successful first spring season! We hope you give late summer planting a try!


Purchase your late summer 2024 Garden In A Box starting June 10! Pick up and plant in late August or early September.

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