Perennial Flower Care and Propagation 

 

As part of our monthly free speaker series, we recently hosted EMGC member JoJo Pingitore who shared a wealth of information about perennial flowers, their care, propagation, and use in landscapes and gardens. 

 

Perennials covered in the talk were the herbaceous (non-woody) types that die to the ground at the end of the growing season, then regrow for two or more years. In comparison, annual plants live for only one growing season. There is a perennial for most any condition in your landscape or garden. Most do well with 6 to 8 hours of sun a day, and differ in bloom time, hot/cold tolerance, water & soil requirements, and plant height & spread. 

 

You can plant a succession of perennials so you’ll have blooms all through the season. It’s fun to supplement your perennials with annuals, artwork, and even lights (just take care with lighting not to disrupt moths and other insects who are valuable pollinators). 

 

Soil is important for perennial health – it’s always good to loosen soil before planting, and work compost into the top 8 to 10 inches of your planting area. Compost can be aged plant compost, chopped leaves, gypsum (which helps break down clay), ashes, biochar/wood vinegar, worm castings, and more. JoJo recommends mowing over your fall leaves a few times so they are chopped small, then collecting them to use as compost! 

 

Don’t be afraid to prune your perennials! Without pruning, some will choke out other plants and take over. Pruning also forces new growth, with can lead to more blooms. It’s OK to hack away at overgrown plants, then trim them regularly to maintain the shape and size that works within your landscape. JoJo explained the importance of pruning to encourage new growth by using weeds as an example – if you only cut the top off a weed, it will grow back again soon. You have to pull the weed out by the root to truly eliminate it. So pruning a perennial will not harm it, but will instead refresh it and force new growth. 

 

Perennials reproduce via seeds, root growth, suckers, and rhizomes.  

 

For those that produce seeds, once the seeds form, the plant thinks its work is done and will die back for the season. If you want the encourage the plant to continue to produce blooms, deadhead (trim) the seed heads whenever they appear. Alternately, you can collect seeds and use them to grow more plants in locations of your choice. To collect the seeds, time your collection for when the seedheads start to turn brown (but before they are dry and split open). Place them upside down in a bag or pot and allow the seeds to dry and pop out of the seedheads and collect in the container.  

If the seedheads are allowed to mature on the plant and are not collected, the seeds will naturally disperse in the wind and you’ll have plants next spring in places that you didn’t plan for. 

 

For perennials that reproduce by roots, suckers, or rhizomes, you can divide them and plant the split-off sections where you choose. Dividing perennials is important to do, usually every 3 years or so. Hints that your plants need dividing are when the middle of the plantings are empty, or the stems appear weaker/thinner than normal. The best time to divide is in the spring or fall (opposite season from when the plant blooms). 

 

Like any plants, perennials are susceptible to disease and insect damage. JoJo provided a wonderful resource list of natural homemade pesticides, fungicides, and herbicides.  

 

JoJo also advised that there are some aggressive perennials that can take over an area. Plan on pruning and trimming to control these, or grow in pots. Some of these are gooseneck, mint, loosestrife. 

 

If you have a perennial that dies out, it may be in a bad spot for its soil or sun requirements, or it may just be old. Perennials do not live forever, and can just die out. 

 

When buying plants, always read the pot labels to be sure the growing zone, plant height and spread, light requirements, and bloom times all work for your garden plans. JoJo also warned that even though we are usually considered to be zone 5 here, some sellers are putting out plants hardy only to zone 6 or higher – these will not survive our winters so are not really perennials for us – read those labels to avoid disappointment. 

 

JoJo also provided informative handouts on deer resistant plants, dividing perennials, and listings of sun-loving & shade-loving perennials. 

 

JoJo recently completed her core horticulture training and is now an official Master Gardener Apprentice! The next step is to complete at least 50 hours of volunteer work within the community to become a full Master Gardener. We are very proud of her and glad she is part of our club!!