Choosing perennials for fast results in your garden

One of the potentially frustrating parts of having a new garden is waiting for it to fill in. Depending on what you purchase, you might end up with a bunch of small plants and a lot of blank space around them — and that's okay! Many perennials are small when first planted and can take some time to grow. I always recommend investing in perennial plants and shrubs for a new garden even though it might cost a little more at the outset. The long-term payoff will be greater than if you just plunk a few annuals down.

If you want something that looks lush and colourful more quickly, there are fast-growing perennials you can choose, and some planting strategies that will give your garden more instant impact. Read on for a few tricks to get things filled in faster. 

Choosing perennials according to the conditions of your garden

To set your perennials up for success you'll first need to know the conditions of your garden. Is it hot, dry and sunny? Or does it get some shade throughout the day? Does the soil drain well or is it constantly wet? When you're looking at plants, read the tags carefully. Most nurseries also have knowledgeable green thumbs on staff who can help direct you to the best plants for your particular garden conditions. Don't be afraid to ask questions.

Consider choosing plants that are native to your area. While you'll still need to make sure they're planted in a spot where they can thrive, these plants are well-adapted to your region's growing conditions, and that's a great advantage. 

Many perennials are best planted in the spring, and not in mid-summer when the conditions are hottest. However lots of sales happen throughout the summer and early fall, and you can still plant your garden then — you just need to pay close attention to the plants until they're established (be sure to water deeply and regularly). 

Garden centres often have return policies that include a warranty on perennials for the duration of the growing season, which means if the plants don't make it, it's possible to return them. I recommend asking your local nursery about their policy and saving your receipts.

Perennials that will grow faster

Start by looking for plants that are large enough to make an impact when first planted. Some perennials come in small pots, usually about a pint or a quart. The plants are smaller, but they'll be cheaper and take a few years to really get going. If you're in more of a rush and don't mind spending the money, see if your plant comes in a one-gallon pot or bigger. If you're looking for shrubs, you'll probably have luck finding larger-sized pots too.

Another thing to consider is having blooms throughout the entire growing season. That means choosing plants that deliver their flowers in the spring and ones that save their show for fall, too. This can help make a garden look more full. Fast-growing groundcovers are great for filling in spaces around younger perennials.

Here are some of my favourites that fill in faster:

Sedum

Also known as Stonecrops, sedum plants are great drought-tolerant choices for any garden. These plants enjoy full sun spots in the garden. Mounding varieties like Autumn Joy will grow into a nice wide ball over time, while ground cover varieties like Dragon's Blood will spread outwards more quickly. 

Hardy geraniums

If you're looking for a nice, mounding ground cover, perennial geraniums (not to be confused with annual Pelargoniums, which are also called geraniums) spread dependably outwards, rather than upwards. They're drought-tolerant and deer-resistant, and can be grown in full sun to part shade.

Catmint

Anything that's part of the mint family will spread, even if planted in poorer soil conditions. And unlike the mint commonly grown as a culinary herb, catmint can be contained. The plants will spread outwards and produce delicate purple blooms. Catmint can be grown in full sun to part shade.

Other fast-growing plants include:

• Salvia
• Coneflowers
• Hosta
• Heuchera
• Coreopsis
• Russian sage
• Black-eyed Susan
• Bee balm
• Ornamental grasses

In the shrub department, look for these:

Ninebark

I fell in love with my Tiny Wine Ninebark because of its abundance of blooms and its deep maroon foliage. Some ninebark varieties have foliage that's more green or gold. Either way, this is a dependable shrub that grows quite quickly and will flourish even after a hard pruning. Plant it in full sun to part shade, in well-draining soil. 

Potentilla

The branches, with their small leaves and flowers, may look delicate, but potentilla is a hardy shrub that can spread by one to two feet a year. Potentillas are cold-hardy, with some varieties being able to withstand temperatures down to –46 C. Plant them in full-to-part sun.

Hydrangeas

Hydrangeas are generally a fast-growing shrub. There are a number of different varieties, all with gorgeous blooms. For some, the eventual width is two to three feet, while others can span four to five feet. Be sure to read the plant tag carefully so you know where to place your shrub based on its eventual height and width.

Bloomerang lilac

Not only does a Bloomerang lilac bloom more than once a season, it can grow to be up to five feet wide! (I will say, it's strange smelling lilac flowers in September.) This is a hardy shrub that doesn't grow too high but will spread outwards. Plant yours in full to partial sun. 

Other fast-growing shrubs include:

• Hardy roses
• Spirea
• Elderberries (I love my Lemony Lace, but Black Lace is stunning, too.)

Placement for immediate impact

Read your plant tags carefully. They will tell you the eventual width and height of the plant, and how far you should space it from other plants. That being said, you can group plants closely together and in clusters to create a fuller look right away and move them later if you need to. 

If you're making over a big garden, a plan drawn up by a professional can help you arrange plants in a way that works best with the space. Look to place the biggest plants at the back or in the middle so that you can see the shorter perennials. Interior design rules for the placement of objects also can be applied to plants. That's the rule of planting in threes or fives. Grouping plants together makes a space look fuller and more balanced.  

Consider sneaking veggies into empty spaces

If you have the right growing conditions, you can sneak some vegetables among the perennials to make a garden look fuller. Dig in a tomato or pepper plant with an ornate cage around it. The veggie will look ornamental and you get the added bonus of an edible crop! Other ornamentals, containers and raised beds can also create height and visual interest. Kale and herbs like thyme and parsley are great border plants.