Do u think these spirea will eventually bloom once the warmer weather comes . Right now they are very spindly and I am tempted to put them out and replace them. Thank u for your help.
Thank you for contacting the Toronto Master Gardeners with your question about your Spirea that are not thriving. You have not given us any details on where your bushes are growing, so this will limit my advice to generalizations. But here are some guidelines.
All plants have different criteria for the soil they like to grow in, the amount of sun and light they need, and the quantity of water they can tolerate. My suggestion is that you check that you are providing these criteria for your spirea before you dig them up. Nurture them as much as possible this year and see if they thrive. They are hardy little bushes, and with a little bit of TLC, they should perk up and provide your garden with lovely colour from early spring to late fall with gorgeous red foliage at the end of the year, and offer you the additional bonus of attracting butterflies and other pollinators to your garden.
The general requirements for Spiraea are: Plant them in soil with a balanced pH that is not fertilized but that is a good loam. Provide them with good drainage; they are drought tolerant. Plant them in full sun to partial shade (4-6 hours of direct sun). Prune spring-blooming bushes after they have flowered. Prune bushes that bloom in summer in early spring.
With this in mind, please add a good layer – about 3 inches — of compost such as composted manure or shredded leaves to your spirea bed. Do not place the compost directly on the trunk of the bush. Redirect the water downspout so that it is not emptying out close to the bushes. Make sure there is no other source of sitting water coming into the bed. But most importantly, check that they have enough hours of sunlight. If they do not, then transplant them to a sunny spot in your garden.
When they get a bit bigger, you should prune them. Directions on pruning and the other needs of spirea can be found in this article by Stephen Westcott-Gratton: gardening guide on spirea
I hope that these small changes will allow your spirea to flourish and give you much joy.
May 6, 2021