People want to see flowers now – as many and as soon as possible. So we go to garden centers and look, perhaps to buy. This region’s garden centers are exhilarating after winter – tropical houseplants, early flowering annuals and perennials, spring-flowering shrubs.
But what are you seeing and when can you put them outside?
What is ‘cold-hardy’?
In professional garden centers and nurseries the signs or the staff should tell you which plants are “cold-hardy” and “hardened off” – ready to put outside. Many annuals tolerate and even benefit from cold temperatures, even 40 degrees. Use them to decorate the patio or front porch, but cover them when the inevitable late frosts hit. Cold-tolerant annuals include Nemesia, Osteospermum (African daisies), pinks, snapdragons, stocks, sweet alyssum, sweet peas and pansies.
As for perennials, one would think they are tough enough to go outside. After all, they were chosen because they survive the winters in our region, right? That is true, but when to place them outside depends on some information: If they’ve been living in a warm shop, flower show or greenhouse, you need to get them used to the cold weather. Also, if they have been forced to bloom way ahead of their normal timing, the buds and flowers aren’t ready for 40-degree nights. Take them in and out, adjusting to the changes gradually.
Do choose some beautiful early flowering plants, but wait until the soil has warmed up before planting them. Depending on your neighborhood and microclimate, that would usually happen in May.
Tests for soil readiness:
1. Feel the soil 5 inches down. Is your hand comfortable or does it feel cold?
2. Crumble some soil in your hand. If it crumbles, it’s ready. If it makes a mud-pie, go back inside.
Fabulous early flowers
In garden centers I have recently seen some beautiful perennials that flower early in the season. Except for hellebores (that have been flowering for weeks), these wouldn’t be flowering outside quite yet, but they will be among the very first performers.
Before the season is too busy, I suggest you ask your own favorite garden center people (the ones who order the plants for each department) what’s new that got them excited this year.
Chris Lavocat, of Lavocat’s Greenhouse & Nursery, East Amherst, showed me some of his discoveries and told me how he went about choosing: “People want what’s new and exotic, but you have to choose what will really grow here ... I look for something unique, like this ‘Storm Cloud’ Amsonia. Just look at the black stems,” he said.
Each garden center has different choices, and I’m betting you and the pollinators will love them all.
Here is a sampling to see now, take home, harden off, and plant in May.
• Amsonia tabernaemontana (Bluestar) ‘Storm Cloud’: This cultivar of a native plant has dark stems and masses of star-shaped periwinkle blue flowers in spring. Another Amsonia (A. hubrechtii) turns bright gold in fall. Average size: 20 by 24 inches.
• Phlox subulata (Creeping Phlox, Moss Phlox) ‘Emerald Blue’ (plus many cultivars in many colors): Typically people ask for this in garden centers after spotting it in a front yard, but they are disappointed to find that it has finished flowering. Get it as soon as you see it, so you will have a lovely spread next year. In the yard, on the edge of a wall or border, it makes a sea of color very early, and a pleasant green groundcover all summer; about 4 inches tall, mats spreading to 2 feet.
• Lysimachia atropurpurea (Burgundy Gooseneck Loosestrife) ‘Beaujolais’: I first spotted this one at Lavocat’s Garden Center and stopped in my tracks. It is stunning, with silvery-green wavy edged leaves and burgundy flowers. I must have it. Its size: 20 by 18 inches. It is the same genus as old-fashioned Gooseneck Loosestrife, but all reports say it will not spread like the relative, and the common name “loosestrife” should not confuse people. It’s no relation to the invasive loosestrife correctly called Lythrum.
• Baptisia (False Indigo): This valuable genus is a legume, with flowers that please many pollinators, presented in a compact, upright perennial with season-long pretty foliage. Older Baptisias offered lovely blue/indigo blossoms. New cultivars have emerged in recent years leading to the Decadence® Deluxe series (Proven Winners) that includes ‘Pink Truffles, ‘Pink Lemonade’, ‘Blueberry Sundae’, ‘Vanilla Cream’, ‘Dutch Chocolate’ and ‘Cherries Jubilee.’ (Does anyone feel hungry?)
• Pansies: These are technically perennials, and efforts in the last decades pursued their winter hardiness, producing cold and snow-tolerant ones such as ‘Icicle’ and ‘Snow Angel’ among others. Whether or not they perennialize, they like the cool weather of spring and fall, so get them going now.
Garden centers don’t all have the plant departments filled out yet. They have to be careful, as do we, about putting plants outside too soon. April weather can fluctuate wildly. But you will find many early bloomers tiptoeing out of their winter hiding places (or being dragged out). So look around. It’s the right time to think about extending your garden’s flowering period to include mid- to late-spring beauties.
Sally Cunningham is a garden writer, lecturer and consultant and author of the newly published book, “Buffalo-Style Gardens” (St. Lynn’s Press, $24.95), along with Jim Charlier.