Focus on Flowers

Air temperatures that hover just above freezing for a prolonged period of time in the spring can kill most tender plants if they’re set out too early. So if you set out your houseplants outdoors too early, even if it’s actually above freezing in terms of the air temperature, they simply can’t endure it after being accustomed to the warmth in the house.
All air temperatures affect plants, as it affects most of their physiological processes such as their absorption of water and nutrients and time of flowering, fruiting, and also seed production. Each plant species has its own critical air temperature, which includes the minimum and maximum temperatures between which a specific plant can continue to exist, grow, and/or thrive. There is the perfect temperature for it to grow optimally and the lethal temperatures, both high and low, when a specific plant will expire.
All these levels are also, of course, influenced by the individual plant’s stage of growth and development. Seed germination requires more warmth than vegetative growth as well, and optimum temperatures are different for both day and night.
The important point here is, of course, do not take risks by setting out your annual plants too soon. Always be cautious for it is better to be sure than sorry when considering when to plant outdoors in the spring.

The weather in our flower garden has to do with local atmospheric conditions: hot and cold; wet and dry; calm and stormy, and so on.
Climate refers to the region’s atmospheric conditions and predictable events for that region or particular place. The US Department of Agriculture (USDA) divides North America into 20 separate zones, and the zone we garden in determines the plants that we can grow.
But as well as the average highest and lowest temperatures that occur in our specific zone, many other factors affect our weather and the perennial plants we can grow since perennials need to winter over.
Frost dates are very important. Gardeners need to know the average dates of the last frosts in the spring and the first frosts in the fall in their area. The date of the average last frosts is crucial so that we know when it is safe to set out our tender annual plants, which would be damaged or killed by a frost. The date of the last spring frost for a zone is like a marker that allows gardeners to schedule gardening efforts.
Of course, there is a difference between usual and average frost dates. We also need to establish how many frost-free days there are in our climate, as this defines our growing season and our options about what we can grow.
There are also micro-climates within our personal gardens: places, for example, where there is more sun, less wind, or more shelter for the plants.
REFERENCE: Gardener’s Guide to Frost: Outwit the Weather and Extend the Spring and Fall Seasons, Phillip Harnden, Willow Creek Press (2003).
NOTE: It is best for gardeners to err on the side of caution when planting spring annuals. If a late frost comes, the plants will be killed if they are planted too early. Annuals do best when the soil has warmed enough so that they can immediately begin to grow in their new location. In my Zone 6 Indiana garden that is usually around Mother’s Day.

Many of us with clay soil complain loudly about it, and it’s true that gardens with clay soil can be hard to dig. Also, with clay soil, it is not a good idea to put a bed in areas where standing water collects.
However, one can have very successful flower gardens where there is clay soil, as it has excellent water-retention, and less water and nutrients need to be added to the soil than are needed with sandy soil, for example.
Plants with tap roots such as coneflowers and Japanese anemones all do well in clay as their long roots penetrate deep down to access moisture during drought. Also, plants that dislike wet feet can be planted on a slope or in raised beds so water will easily run off.
Bulbs do well in clay, as do shrubs such as hydrangea, lilac, spirea, dogwood, viburnum, kerria, and yew.
Trees such as river birch, willow, crabapple, and serviceberry also like clay.
Perennials such as asters, daylilies, baptisia, hellebores, hosta, irises, coreopsis, and black-eyed Susans also thrive.
While fast-draining sandy soils need frequent watering, once clay soil is well saturated during a rain storm, gardeners don’t need to provide nearly as much supplemental watering for days. So, during dry spells, be thankful if you have moisture-retentive soil. — “Clay is okay!"

Plant families are like human families in that successive generations of their members often have improved looks, health, longevity, and vitality.
This is certainly true of the latest versions of the heucheras, commonly known as coral bells. So many new heucheras are now available in many different foliage colors and combinations. The flowers themselves, spires of tiny florets that are raised high above the leaves, have not changed much but the leaves are almost unrecognizable when compared with the ordinary green leaves that this family of plants had in the past.
If you browse online you will be amazed by the new generations of this common shade-loving perennial. The fanciful names evoke wonderful visual images of each of the new heuchera varieties. For example, ‘Forever Purple’, ‘Georgia Peach’, ‘Cherry Truffles’, and ‘Carnival Limeade’ give one an idea of the single-colored purple, peach, cherry, and lime foliage.
But, there are also bicolor leaves featured on some of the new varieties. For example, ‘Red Lightning’ that has handsome chartreuse leaves with red veins and ‘Cinnamon Curls’ with cinnamon curly edged leaves.
The photos in catalogs and online of this new plant generation are irresistible. I plan to order as many as I can afford for spring planting!

At this time of the year we usually read about gardens instead of gardening.
I have been reading about deadheading—the way we ensure plants keep blooming by chopping off the spent flowers. This prevents them from forming seeds, which is a signal that no more flowers are needed by the plant.
Annuals have to produce a lot of flowers because they only live for one year and so have only one flowering period to procreate. Perennials, on the other hand, have a second way of continuing in life: they can grow back the next year on their own roots so setting seed is not so crucial for them. That means that we don’t have to snip off every spent flower on the perennials, (though it does increase their vigor), the way we should with our annuals to keep them blooming. Most perennials will only bloom for a few weeks anyway.
However, the whole garden looks better if plants are deadheaded, so it is a good thing. You can snip each flower off individually, or you can cut back a plant that has finished flowering by snipping half of the plant off with shears.
Colorful flowers attract pollinators that fertilize them, so annual flowers are often especially showy as they need to be pollinated in a shorter time frame in order to perpetuate themselves. This is why we need a sequence of different perennials that bloom at varied times to have continuous perennial blooms in our gardens. Many of us find that deadheading is a calming repetitive activity that we enjoy, so we do a bit each day all through the growing season. It keeps the color coming.