The best plants ever
Mark Cullen tells you how to grow them,
Welcome to the opening act of the planting season. This is the May 24 weekend (as opposed to Victoria Day weekend!) and everybody is happy: cottagers, golfers, tennis players — but most of all, gardeners. They are grinning from ear to ear. The plant material at retailers this weekend will be unmatched for selection and quality: when plants arrive from the growers, they are always in peak condition and never look better.
Last week I explained how to shop for the best performing plants — read it on thestar.com.
This week I am offering my Top 10, red-hot tips for growing the best plants. Ever. Who knows, you might even win Canada’s Best Garden Street and $1,000 of Mark’s Choice garden product will be yours. Go to gardendays.ca for details. 1. Go straight home. You have worked hard at finding the best quality plants at your favourite retailer and placed them safely into the trunk of your car. Now go home. Your car trunk is not the best place to store plants that were thriving just days ago in the warm hug of a greenhouse. This massive understatement is another way of saying that your trunk becomes a solar oven when you park in mall parking lots (which are notoriously short of mature shade trees). 2. Find the shade. Fresh plants are soft, especially annuals and perennials that have been delivered straight out of a greenhouse to the retailer. They need a little time to adjust to outdoor temperatures, the intensity of the sun, and to the wind. Place your new charges on the east or north side of your house or a fence. Check them for dryness and apply a 20-20-20 water soluble fertilizer to help nurse them into their new surroundings. If you are not planting them the same day, keep an eye on them for water daily. 3. Plant the small ones first. Take stock of the plants that you purchased and try to get the small ones in the ground first. They are happiest there. The insulation of the new soil provides a great new home. The flip side of this theory is “the larger the plant and its container, the longer it will survive out of the ground.” It is all about soil volume. 4. Soil prep is everything. If you are a parent, you will remember the debate over what you were going to feed your kids when you brought them home from the hospital. Breast milk or formula? What will be their first solids? You get the idea. You need to have the same thought process where plants are concerned. I use a huge volume of compost in my garden and you should do the same. I use about 40 cubic yards, but I have a 10 acre garden. Look for bagged product that is certified “bio max” by the Compost Council of Canada (Compost Quality Alliance) for the very best quality cattle and sheep manure and shrimp compost (which is high in calcium). 5. Your existing soil is OK. If you have been adding lots of compost to your soil over the years, it is OK but not great. Add compost to each hole and stir it up with a trowel or shovel before planting. If your soil is made up of solid clay or sand, dig it up, create a generous hole and backfill with triple mix (equal parts compost/peat moss/top soil). 6. Container soil is OK, too. The containers previously put on a good show in your yard may still hold the soil from last year. Put this in your garden, spread it around the roots of existing plants: it’s not bad, it’s just not good enough to grow a new crop of plants in this year. Replace it with a quality potting or container mix. Look for a brand you trust as there are some cheap mixes out there that don’t produce cheerful plants. 7. Plant food. I don’t fertilize most of my plants throughout the year as all of the nutrients they need are in the compost that I dig in so generously (see point No. 4). When I plant a tomato, for instance, I put a bushel (about four shovels full) of compost and sharp sand in the hole. There are plants that require additional food despite my rich soil: roses, for example, are heavy feeders. I fertilize mine with a Feed and Forget product once early in the season (like now) and that is it for the whole year. I add sulphur and fertilizer to my rhododendrons and hydrangeas and evergreen food when coniferous plants are looking stressed and the foliage is yellowing. 8. Water. Or rather, don’t water. Nine out of 10 plant problems in the garden relate to over-watering. Let the soil in your garden dry at least 4 cm deep before you apply water; for containers, make it 3 cm. Use your finger to determine the need to apply water and, when you do, be thorough. Sprinkling the soil just encourages shallow roots which, in turn, creates plants that are not very drought tolerant. Having said this, it is important that you water your plants into their new hole at the time of planting. Be thorough and take your time. 9. Rainwater. Speaking of water, I have four rain barrels around my house and they are amazing. As rain falls it picks up oxygen from the air and becomes charged with it. I use rain-barrel water on all of my container plants and I am always delighted with the results. Try it. Rain water is warm, too: you can bet that your plants love that! 10. Fertilize containers. The space that your containerized plants have to grow in is limited by the size and shape of the container. With a limited mass of soil from which to pull nutrients, it is important that you augment it with fertilizer. I use a slow release product, similar to the rose food that I mentioned in No. 7. This once-and-done formula is labelled for use specifically in containers. I recommend it, as it reduces the fussing required with watersoluble formulas and it really works well.
Take a daily walk through your garden and look carefully for insect infestations and diseases; if you spot trouble, check out my website at markcullen.com.