Setting the birdbath straight

I awoke last Saturday morning to the lilting song of a robin — they’re back! Each spring we have separate pairs of robins claiming the front and back gardens, and territorial issues are avoided with generous bathing provisions in both areas. We have three baths—two in the larger back garden and one in the front. After years of experience with robins, I know that robin song outside my window has less to do with the joys of spring and is more likely an insistent bird noticing that his or her bath is dry.

And so the day began with a search for the garden bucket, which needed to be filled at the kitchen sink as water isn’t yet turned on in the garage. The water bearer (i.e., the gardener) arrived at the birdbath to find that, indeed, all was not right with the bathing facility. Not only was it dry, but winter frost had heaved the earth underneath and the birdbath was noticeably tilted, causing the water to run to one side and mostly spill out. I suppose it would have done in a pinch, but quick alterations were necessary if a decent family of robins was to be serviced. Unfortunately, this required some heavy lifting.

Although the winter garden seems dormant and stationary, frost is actively at work underground. Soil expands as ground moisture freezes, changing stairway elevations, lifting pathway stones, tilting birdbaths and heaving some plants right out of the ground. Settling plants back into their place is easy work, but getting a birdbath straight involves rebuilding its foundation.

The heavier a birdbath is (and also consider the weight of its volume of water), the stronger and deeper a foundation is necessary to resist frost movement and keep it upright and straight. The weight of a concrete birdbath placed directly on the ground causes the soil underneath to settle unevenly (tilting the bowl) in a matter of weeks. Placing a flat stone (like a flagstone) under the birdbath to evenly distribute its weight keeps things straight for the first summer, but it’s likely frost will shift soil underneath and tilt the stone and bath over winter.

I’ve made two kinds of foundations under our birdbaths, depending upon energy and materials at hand. The most elaborate foundation was made for an oversized concrete bath, and involved excavating a hole, putting a four-inch (10-cm)-deep layer of large-size gravel in the bottom, and setting two concrete blocks into the hole. The space around the blocks was filled in with more gravel, and a large flagstone laid on top, with the birdbath resting above. That foundation hasn’t noticeably shifted in 12 years.

But I didn’t have any concrete blocks in the cupboard this time. Instead, I removed the birdbath bowl and pedestal, lifted the large flagstone it was sitting on, and dug out and set aside the six inches (15 cm) of gravel that was underneath. The previous foundation wasn’t deep enough (hence the shifting bowl and water level above), so I dug a hole about 12 inches (30 cm) deep and wide, filled it with more gravel and two vitrified bricks (glazed and hardened to make them impervious to water) at the top, surrounding them with gravel, flush with the soil level. Then I put the flagstone over the bricks, and used a spirit level to be sure it was straight, making a few adjustments until it was. I stood the pedestal and bowl on the flagstone and poured in the water, the test of just how level this construction was. There was only a slight difference in water level from one side of the bowl to the other. I can live with that, and the robins will have to as well. And all this before breakfast!

First species crocus

The Tommie crocus are up! These are the species Crocus tomasinianus — shy, short and delicate little gems of early spring. Their thread-thin necks and pale mauve petals with yellow centres gleam against the drab brown soil, providing colour in the gap between snow melt and the first green sprouts of perennials. I have both the species bulbs with petals so thin the sunlight shines through them and also the hybrid ‘Whitewell Purple’, with rich purple petals of slightly thicker substance.

These early bloomers are collectively known as snow crocus, and contain species that reproduce from seed and bulb offsets. I’m fond of striped crocus, like C. vernus ‘King of the Striped’ (syn. C. vernus ‘Striped Beauty’), with irregular purple stripes against pale mauve petals. C. vernus ‘Pickwick’ appears more robust with deep purple veining reaching up the tall mauve petals. C. chrysanthus ‘Prince Claus’ (syn. C. chrysanthus ‘Prins Claus’) is a bit different, with milky white petals gilded by deep purple flushes with feathered borders.

The early purple crocus bloom with acid-yellow winter aconites (Eranthis hyemalis), making pretty purple and yellow partners. In my Zone 6 garden species bulbs reproduce very slowly, and occasionally I find single blooms that must have come from seed. I’ve read reports of Tommie crocus spreading with thick clusters of seedlings in warmer regions. But the few I have return reliably every spring, and we are old and good friends.

It’s truly spring and I hope you’re busy in your garden. Thanks for visiting me at Making a Garden, and I’ll see you next week.