I was shocked to see that a post I wrote just about this time last year featured the same dirty snow and cold temperatures we are having right now. It’s easy to forget that as a winter month, March can be only slightly more moderate than February. As a spring month, it is stingy with both the sun and moderating temperatures. March can go either way, and neither way is particularly wonderful. This year, I still have my nose pressed to the glass, looking from the inside out. It was 12 degrees this morning, and barely better by 3pm. But we have had more sun the past few weeks than all of January and February. We have a little warm and sunny weather streaming through the windows.
Our helleborus festivalis held over the past 3 days drew lots of gardeners looking for some sign of spring. Many commented that the greenhouse smelled like life. My observation? I could hear gardeners exhaling their dry winter air. The shop smelled fresh. Sun was streaming in every window. Lot’s of hellebores went home to good gardening families.
I have never been a fan of plants in the house. In my opinion, plants belong outside. Whether in the ground or in pots, plants need fresh air, the sun and rain from the sky. A plant stuck indoors is a plant longing for another time and situation. But this very cold and still snowy late March is a situation few plants could endure outdoors. Indoors, they make the lack of a garden for me to tend a little easier to endure. Handling garden plants indoors is different than handling tropical plants indoors.
My house is hot, dry, and dark, by plant standards. The heated house air has just about no humidity. The light inside my house largely is courtesy of the miracle of electricity. That light is miraculous for people, but not so swell for plants. I might be able to get some tropical plants with a very low light requirement to live. But tropical plants don’t so much interest me. I am ready to garden. Can garden plants live indoors long enough for me to take them, and me, outside? I do have some sunny window sills. Given my need for some signs of green life, there are plants that will oblige.
I would not say that any plant loves to be grown indoors. I would say that a fair number plants tolerate life indoors. Some low light tropical plants have the ability to adapt to interior conditions for years. The successful culture of tropical plants indoors is not my expertise. My interest in plants inside the house is confined to living through the madness I call March. Some garden plants will tolerate a short stint inside on a sunny window sill, providing certain cultural conditions are met. Spring flowering bulbs, once their requirement for cold has been met, will send forth leaves and bloom stalks in a low light too warm interior environment. Don’t expect them to love the house for long. Luckily, lots of nurseries carry pots of forced bulbs. Buy lots, and stock your sunny window sills. Restock when you need to.
Lemon cypress is not hardy in our zone. Hardiness zones refer to the hardiness of the roots of a plant-not the tops. Lemon cypress can actually tolerate a good bit of cold. Should you see a lemon cypress now that you have a mind to grow on this summer, chances are you can bring it along on that sunny window sill until the night temperatures are warm enough to move it outdoors.
Helleborus orientalis, and its hybrids, are incredibly cold tolerant. They stir in late March. They send up flowering stalks in April. They are glorious in bloom, in late April. In May, and in to June, the green tepels still look great. Can you hold them indoors until the ground is ready to be worked? Sure. Give them the sunniest window sill you have. Enjoy those gorgeous flowers. Go easy on the water. Garden plants do not transpire or grow so much indoors. If they are not growing so much, they don’t need so much water. Though they appreciate some sun, they would not appreciate the cooking heat from a radiator or heat duct.
I have kept ivy topiaries in the house over the winter plenty of times. I err on the side of dry. I give them the best sun I have. A sunny window sill indoors is but a small shadow of a sunny place outdoors. For plants lacking sun, dial back the water. Plants in full sun outdoors transpire a lot, and need a regular drink.
Myrtus communis is an evergreen shrub in zone 8. They like full sun, but will tolerate some shade. What they will not tolerate is getting too dry. As they are willing to be trained and pruned into topiary forms, they are a popular garden plant for indoors for the winter season. Garden plants that are being grown indoors are not so much growing on. They are holding on until they can get back outdoors. This makes growing myrtle topiaries indoors dicey. They need just enough water, not too little and not too much. They are much easier to kill than grow. As for the table in the above picture, do not try this at home! Myrtle topiaries may look great on your dining room table or mantle, but they cannot be grown in the dark.
Myrtles grown indoors are great on an interior table for a party, or a weekend, but any longer that this in the dark will bring trouble. Plants need light to survive. Some gardeners buy myrtle topiaries in pairs. One sits on the kitchen counter while the other has a sunny cooler sill. Once every 3 or 4 days, the plants switch positions. Forced spring flowering bulbs are much easier to keep indoors than a myrtle topiary. Once they start to grow, they are programmed to bloom. They will do their destiny unless impossibly challenged.
The idea is just to have a small sign of the garden inside the glass. Long enough for the season to turn.
My office has very deep window sills, and faces south. There is room on them to bring on some rare hellebores that were only available as very small plants. The windows are very tall, so the space is light. I have to look in on them over every day, watching the water, and turning the pots so every side gets some of that sun. What started out being a chore has become a ritual I am enjoying.