Early Spring Planting

April 19, 2014 (2)Planting containers for early spring has its pleasures and its pitfalls.  The overriding concern is always the cold.  We planted containers for a client in downtown Detroit Thursday and Friday of last week-a dicey move, considering the overnight temperatures were very cold.  One night-22 degrees.  How to best avoid cold damage in early spring is to be sure you are using plants that have had the opportunity to become accustomed to, or the inclination to tolerate the cold.

April 19, 2014 (8)Very few plants thrive in cold weather.  That does not mean that they will not adapt and tolerate it.  This project was planted solely with plants that had been sown and grown to a good size last fall, prior to being wintered in a cold but not freezing house.  The pansies had had months to become accustomed to cooler conditions.  Placing them outdoors in cold April weather did not send them into shock.

April 19, 2014 (31)Gardeners who start their own vegetables from seed indoors know that those seedlings need to be hardened off before placement in the garden.  Hardening off is a process of exposing seedlings to the reality of seasonal weather, a little bit at a time.  A few hours a day in a shady place, then the day outdoors in the sun.  Then a planting in the garden.  Early vegetables that are sown directly in the garden do not experience transplant shock.  Pea seeds can be sown when the soil is workable, and the soil temperature is 45.  However, peas that that has been germinated or grown in a warm greenhouse will react poorly to a drastic change in environment.  Easy does it.

April 19, 2014 (22)The same would be true for spring flowering perennials.  Some growers  winter their plants in tunnel houses with no heat, so they are subject to the same cold conditions as perennials already planted in the garden.  Other growers pot up bare root perennials in early spring, and bring them on in a warm greenhouse. A hothouse grown perennial may react poorly to being put outside without a hardening off period.  Forced pots of hyacinths need some limited exposure  to the elements before they are placed in a spring container.

April 19, 2014 (27)Lime leaved heucheras do not have much tolerance for cold.  The leaves will bleach, and go limp.  However the heuchera Creme Brulee  seems to shrug off the cold.  I have had angelina survive the winter in a small pot I had forgotten to get in the ground.  But moved outdoors from a warm greenhouse to a cold garden will cause the needles to color up orange and red.  This not so spring like look results from the plant’s inability to absorb potassium from the soil, due to cold.  If your zonal geraniums have red tinged leaves, they are out in the garden too early.

April 19, 2014 (24)There are plenty of plants that can handle the transitional season known as spring.  And having good success with them becomes easier if the plants have been properly hardened off.  The hellebores we had in our greenhouse in March were kept at just below 50 degrees overnight.  Once the season moderated, we moved them outdoors on carts for the warmest part of the day.  When we moved them outdoors for good, we placed them underneath our benches, in the shade.  Even a sunny greenhouse is not near the light intensity of a full sun location outdoors.  Plants exposed to the sun too abruptly can be scorched by sun and wind.

April 19, 2014 (17)Any plant that is already outside at a nursery is good to go for a spring container.  Small spring flowering shrubs are great in containers, and provide some scale.  Twigs and dry or preserved materials can add some heft and presence.  Perennials that look good in spring containers include hens and chicks, lady’s mantle, brunnera, columbines, coral bells, angelina, lavender and hellebores.  Spring vegetables and herbs such as peas, lettuce, cabbages and kales, bok choy and chard, rosemary and parsley, look great in pots.  Pansies, violas, ivy, sweet peas, alyssum, and fuchsia can provide so much color and fragrance.  If in doubt, harden off.

April 19, 2014 (15)My summer pots usually go on long into the fall.  They have the opportunity to get accustomed to the coming of the cold over a long period of time.  Petunias, verbenas, million bells, creeping jenny will look great until frost, having been planted in late May.  If you want to plant them in the spring, give them some time to adjust to the outdoors before planting.  Some gardeners cover their spring plantings for a week or so with floating row cover.

April 19, 2014 (14)A quick introduction to weather that is too cold can set some plants back such that their growth is stunted.  Some never recover.  Much better to celebrate each season, in season.

 

 

Culture

hellebore-collection.jpg
Don’t let the title of this post make you think I am all in and over my head. I have no plan to discuss culture, as in the cumulative arts and intellectual achievement of a neighborhood or nation or region or era.  I would be over my head.  I am interested in culture as the process of making something grow.  Scientists are able to culture bacteria in a petrie dish, loaded with whatever medium known to make bacteria thrive.  Knowing what it takes to make bacteria multiply may help to discover what might starve them off.  Cultivation is an agricultural term dating back centuries.  Farmers do what they can to provide optimal growing conditions for the seeds of any plant they wish to grow.  Gardeners cultivate plants in their garden.  Any plant you choose to grow the idea implies a willingness to provide optimal conditions.

potting-hellebores.jpgThe plant of my current moment is helleborus orientalis, and its hybrids.  A cultivar is a shortened version referring to cultivated varieties.  Some hybrids of hellebores have poor foliage, or are shy bloomers. Others are not especially hardy, or the flowers may be buried in the foliage.  Some cultivars have muddy colors, or poor form.  Others have no inclination to grow.  Plant breeders are an individual lot.  They have a very personal and usually very long range plan to breed cultivars that grow vigorously, bloom profusely, are hardy and disease resistant.  Every breeder has a different idea of what constitutes the holy grail.

spring-pots.jpgHelleborus orientalis and its related hybrids or cultivars thrive in light to medium shade, in well draining compost rich soil that has a source of regular moisture.  My hellebores are planted in full sun, but I am careful to provide additional water during dry spells.  I do not fuss over them much.  If you cultivate hellebores in conditions that approximate their ideal siting, they will probably do well.  The not fussing has a deeper meaning.  Plants that appreciate and thrive in compost rich soil implies they like places where the falling leaves are allowed to rot.  Those places not subject to an inordinate amount of cleanup.

potted-hellebores.jpgI do not cultivate the soil around my hellebores.  If a hellebore is inclined to seed, it will do so with abandon.  Scraping the surface in anticipation of weeds might well eliminate any seeding..  Turning the soil may turn under all the germinated babies.  Even hybrids of helleborus orientalis resent too much attention.  Most plants come equipped with an incredible will to live, standard issue.  I cultivate my landscape with as light a hand as I can manage.  I try not to interfere too much, unless there is a genuine call to action.

spring-blooming-hellebores.jpgIf you would like to grow hellebores, chances are you have a spot.  As beautiful as they are, they are not so fussy.  Deep shade means you will have fewer flowers.  Deep and dry sandy shade-they don’t love this so much. Maybe another species of hellebore would be better, if this describes your conditions. A quiet spot in compost laden spongy soil in light shade-just about perfect.  I try to site my plants in locations that I believe will encourage them to grow and prosper. This is plant culture.

helleborus-orientalis.jpgAs for the hellebores in the greenhouse now at Detroit Garden Works, we keep the space cool.  We run our greenhouse fans non stop. Good air circulation is a good idea for perennial plants being cultivated indoors. We don’t water these leathery leaved plants until they really need it.

growingt-hellebores.jpgThe requirements for the successful cultivation of hellebores in the garden don’t so much apply to growing them in pots.  They make a great centerpiece for a spring container for a sunny window.  Rob has been potting them up all day today.  He has chosen to pair these blooming cultivars with cut stems of curly pussy willow, and a top dressing of natural moss.

pussy-willow.jpgThe hellebores in the ground in my garden are buried under 5 feet of snow-this is today’s news.  I cannot begin to predict how my hellebore garden will do or not do this spring. This has been a winter with which I have no familiarity or experience. In the meantime, am enjoying potting up hellebores in a way I believe will hold them just fine until I can work the soil in my garden.  Rob has paired his hellebore pots with fresh cut shoots of curly pussy willow. He is cultivating spring, as only he can.

hellebores-in-bloom.jpgClose by?  Stop in.

Planting For Spring

Word has it that we will have night temperatures in the teens and up to 20 degrees tonight-welcome to spring in Michigan.  My tulips that are four inches tall-I am hoping blistered and burned foliage will be the only damage.  As for my crocus just barely representing themselves-who knows.  But as tough as spring can be, there are those plants that are resistant to temp troubles. The charteuse leaved geranium, Persian Queen, can take a lot of cold.  Should the cold linger, it will languish; I am not a bit afraid to plant it out April 15, and hope for a steady warm-up.  Osteospermum handles cold even better-these daisies that come in a wide range of colors last long into the summer as well.  Petunias roll their eyes, and are moodily tolerant-don’t count on them to grow now how they do in hot weather.  Alyssum-the workhorse of the spring garden that moves on into summer without any fuss.

Pansies and violas are a mainstay of a spring garden.  I do not use the word mainstay lightly;  the longevity of early spring perennial blooming hinges entirely on the weather.  Should we have an early warm up, or a late freeze, they fade.  Pansies and violas take the ups and downs with equanimity.  Some hybrids survive our winters after a fall planting.  This is worth some flag waving; in the fall,  I can bury tulip bulbs, and overplant the surface with pansies-the spring gratification far outweighs the winter delay. 

Heuchera has seen a breeding explosion like few other perennials in recent years.  Peach, orange and lime foliage-these leaves are seductive. The black leaved varieties don’t send me.  Black foliage to me is about drama-what drama is there in a black leaved plant that grows 6 inches above ground level?  Black leaves on a dirt background-mud, in my mind. I have never been much of a fan of heucheras in the garden-they need division too often for me.  In pots, they shine; I plant them all the time.  Their color and shape is beautiful-up close to the eye. 

I have an aversion to empty pots come spring-they look so forlorn. One’s winter stick center can be kept on through the spring, but I want to see some real plant life going on, early on.  My gardening season is short-best to plan to savor every day. 

Empty pots at the front door do not exactly say welcome. Nothing in the ground is making much of a move yet-save the hellebore flowers.  A nation of hellebores would not warm up this front door-they have an entirely different seat on the garden bus. Low to the ground, they are not so hard to pass over.  They need an intimate, traffic stopping space to shine. I am truly sorry they are not more widely grown.  However, the fact is, once nurseries get good traffic going on in the spring, the hellebores are finished blooming, and sit there on the shelf,  benignly green.  It is easy to miss them.  When I see my patches of crocus push up in the spring, I always regret that I didn’t add to them last fall.  Gardeners need to be six months ahead of the season-how hard is that?  

Though spring plants tolerate cold, they thrive in warmer conditions.  These south side window boxes put on weight from the moment of planting.  The Persian Queen geraniums never skip a beat, and will still look great come October.  How lobelia grows here defies everything I had come to believe about lobelia.  They will thrive in full son on the south side, if the watering is dead on.  This picture was taken the end of June, after an April 1st planting.

This lead egg cup from the Bulbeck foundry in England is a focal point in this garden.  It would not do-for it to be empty in the spring.  Too many other spring views depend on its state of dress. The shape, arrangement and placement of landscape elements in this garden look good, given how early the season.  A Bulbeck stuffed with spring plants-beautiful.


The plants of spring are specific in their color shape and habit.  Once the season passes, that look is gone.  A long spring-this I like.