Written by davethetreecenters • January 25 Trees and Shrubs for Alkaline Soils – Part 2
A couple of weeks back we started this two-parter on choosing plants that will grow well for you if you have alkaline soil. If you are looking for some suitable trees, or are not too sure what all the fuss is about ‘alkaline’ and ‘acid’ soil, check back with that first part.
Once you have the skinny on all that, and now want some ideas for shrubs, read on. . .
Shrubs that Love Lime
OK, so you have adjusted to growing those azaleas and camellias in pots – and if you didn’t already know it, that’s the best way to enjoy their beauty if your soil doesn’t want to co-operate – and you now want to fill all those spaces in your garden beds. Don’t despair, because it turns out that many of our most loved shrubs, suitable for sun or shade, and flowering anytime from spring to fall, are happy in alkaline soils. In keeping with the importance of planting for color and interest across the seasons, let’s take a look at some of them, starting with spring and working our way to fall.
Lilac – Syringa
Nothing says ‘spring’ like lilacs, and if you live everywhere except for the hottest zones – and that includes you, gardener in zone 3 – then these are indispensable shrubs for alkaline soils. They thrive in the northeast, and often in the Midwest too, and in colder zones these wonderful shrubs, full of nostalgia and heirloom beauty, are essential. We can divide lilacs into two main groups –medium-sized ‘French’ lilacs, renowned for their large, perfumed blooms, and smaller shrubs, too often overlooked, that are great for color anywhere in the garden. See our current selection of beautiful lilacs.
French Lilacs – the story goes that Victor Lemoine, a French nurseryman, was trapped at home by the war between the French and the Prussians. Like so many people under lockdown, he developed a hobby – plant breeder. He started with a pretty unassuming lilac that had many petals in each flower, and he and his wife (who was a genius at the tricky task of cross-pollinating) created about 200 amazing plants, with huge flower spikes, stunning colors, and rich fragrance. They were sent all around the world, and became the ‘French’ Lilacs we still grow today. Since Lemoine other breeders have added more, but that broad name is still useful. These are mostly larger shrubs and small trees that will make spring in your garden a time of wonder and beauty.
Shrub Lilacs – it’s probably best not to get carried away with French Lilacs, if you don’t have a large garden – better to use some of the smaller bushes, that grow just 4 to 6 feet tall. These often have smaller flowers, but they are profuse bloomers, and often more suitable for modern gardens. Take a look at the Fairytale® range (with names like Prince Charming, or Thumbelina) – beautiful creations indeed. Or the reliable and more well-known ‘Miss Kim’ – perfect for filling out medium-sized beds. If you are disappointed when spring is over, then get a Boomerang lilac, which does indeed come back again, with later blooms all through summer.
Barberry – Berberis
Modern gardens rely on colored foliage like never before. Today we have a rainbow of plants with leaves in gold, red and purple that brighten your garden for month after month. For alkaline soils, turn to the barberry for help, and with so many to choose from there are colors for everyone. Use barberry for edging or hedges – they clip into lovely dense forms – or beneath windows, where their one fault (thorns) becomes a security asset, deterring intruders. Plant them together, with dark-red leaves in front of gold, for example, or to brighten beds that have finished blooming. One thing is for sure, not only will they thrive in your alkaline soil, these tough, drought-resistant guys will thrive just about anywhere – the perfect choice if you don’t think you can grow plants. If you live in an area where old-fashioned forms of this plant have become invasive, don’t worry, just choose one of the many varieties that don’t seed – all our plants are clearly marked for that.
Butterfly Bush – Buddleja
As spring turns into summer, many of our favorites – like those lilacs for example – have finished blooming. Where to turn for color in late summer and into the fall? The answer is to check out our Butterfly Bush page, where you can find a big variety of these easy shrubs, that do indeed thrive on alkaline soil. All enjoy lots of sun, good drainage, and yes, alkaline soil too. They like it hot and dry, so once you have settled them in, all they need is their annual haircut to love living at your place. If they aren’t invasive where you live, revel in old-fashioned beauties like ‘Black Knight’, or ‘Royal Red’. If you like your spikes big, but your bush small, then the tough little Pugster® series is for you. We have too many that are non-invasive to list, and if you thought butterfly bushes only came in pinks or blues, think again and plant ‘Honeycomb’, with unique balls of golden-yellow blooms in large spikes – it’s a show-stopper and just as loved by butterflies as all the others.
Every garden has some shade, and for all but the darkest corners, every garden needs hydrangeas. Not only the perfect way to fill shady corners, these bushes thrive in alkaline soils – at least if you don’t want blue. Grow those in tubs and pots, where you can easily have perfect blue every time. For wonderful pinks and whites, alkaline soil is perfect and hydrangeas thrive in it. It’s best to split hydrangeas into ‘cold’ and ‘warm’ areas, so you get the results you want. See our full range here.
Zone 3 and 4 – although just as happy in zone 8, there are a group of hydrangeas that bloom well in colder areas, and fill the later weeks of the summer and well into fall with lots of color. Consider the ‘oldy but goody’ that is ‘Annabelle’ – huge rounded heads in pure white that turn pink when the mercury falls. Or the great modern varieties bred from the panicle hydrangea (your grandmother’s ‘PG Hydrangea’), such as ‘Limelight’ for fashionable lime-green and white, or ‘Firelight’ for rich dark pink. If you can’t make up your mind there are the two-tone varieties ‘Vanilla Strawberry’ or ‘Pinky Winky’.
Zone 5 and up – the classic mop-head hydrangeas have been re-worked, and now most bloom not only in spring, on the older stems, but in summer too, on new growth. Take a look at ‘Summer Crush’ or ‘Red Sensation’ for rich pink-reds, or for something very different, grow ‘Alice’, an oakleaf hydrangea that does indeed have ‘oak leaves’, and is a special form of a native shrub that is great for hotter and drier places than other hydrangeas enjoy.
There is More. . .
This is just a sample of the many plants that grow in alkaline soils – we haven’t even looked at Forsythia, Weigela, Osmanthus, or a host of others. The moral is, though, that alkaline soil is no barrier to having a diverse and colorful garden – and don’t let those ‘acid-soil snobs’ tell you different!