Heirloom Expert: Annuals vs Perennials

Doug Oster offers advice on transistioning from a garden of annuals to perennials.

corydalis lutea

Corydalis lutea is a superstar of a perennial. It starts blooming in the spring, reaches its peak in midsummer and continues to put on a show past frost. It will thrive in dry shade, be happy in part sun and forms a colony in just a few years.

Photo by Doug Oster

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I like planting impatiens, marigolds and other annual plants in my Wisconsin garden but I’d like to start using less of them and more perennials. What advice can you give me?

Welcome to the party ... the celebration of perennial plants. They return each season and in many cases get bigger over time. Lots of varieties can be split and either moved somewhere else in the garden or given to friends.

Fall is a great time to plant perennials and there are thousands of choices, which can be daunting. Over time, gardeners figure out what they like and what works in their gardens. This journey of discovery can last a lifetime; for me it’s not a chore, but a thrill. I love spending time carefully looking through catalogs for plants that will thrive for me. Going to local nurseries is another favorite thing to do. I always tell gardeners, don’t shop at a garden center like at the grocery store; briskly walking between aisles in an attempt to get out of the store quickly. Take your time and poke around in every corner in search of rare plants and great deals. There’s something about being around all those plants that will make you happy.

Look at the right plant for the right place. Sun lovers and shade plants should be planted in their respected areas. The same is true when considering what plants to put in well-drained soil in low-lying, wet areas.

At this point I’m often asked what to grow. I can tell you what works for me, but that doesn’t mean it will work for you. Find plants that interest you. Maybe the plants have a connection to your parents, grandparents or friends. Other times we just fall in love with a plant and figure out how to make it grow.

Being notoriously cheap, I love the challenge of growing them from seed. There are multitudes of heirloom seeds that will provide a garden filled with beautiful and fascinating varieties. Once the plants are ready for the garden, there’s work to be done to ensure their longevity. Improve the planting area with organic matter like compost or well-aged animal manure. It’s great if an entire bed can be done, but that’s not always possible. Each planting hole can be filled with the organic matter. Perennials can outlive the gardener, so the soil needs to give the plants everything they need for decades.

These plants will enjoy being planted in the fall when the temperatures are conducive to root growth instead of top growth. The perennials will become established and will be ready to go in the spring. They should be watered in when planted and then mulched.

There’s one perennial that will bloom most of the season — it’s the plant that makes my garden look like someone is actually working in there. Corydalis lutea starts blooming in the spring, reaches its peak in mid-summer and continues to put on a show past frost. Gray, greenish foliage is covered in 1-inch yellow flowers reaching up to about 18 inches. It will thrive in dry shade, be happy in part sun and forms a colony in just a few years. The plant throws seed everywhere and you’ll be happily surprised to see the plant coming up in the most unexpected places. I love it!