By Dave Zeldon and Ely Schweyer

As plant people, we’ve all experienced that moment when we realize the novelty phase of that plant we brought home from the garden centre has worn off. The plant isn’t standing quite as tall, the flowers aren’t as bold, and the leaves are unravelling smaller or not at all. What is this magic they perform in the greenhouse? Perhaps you’ve provided sufficient lighting and adequate watering; there’s just one thing that is often overlooked because dirt is dirt, isn’t it?

  97% percent of plant tissue is made up of carbon, hydrogen, and oxygen pulled from the air and water, the remaining 3% is comprised of 16 other elements taken up from the soil. The quality of soil then is crucial to your plant’s health. Whether your plants are in pots or in ground, each soil type you could provide your plant offers something unique and may lack in another.

*Clay particles are even smaller than silt particles.

Resist the Urge to Slam Your Plant in Potting Soil

There’s bags and bags of rocks, sand, bark, manure, and moss on the shelves, yet the common buyer seems to always opt for potting mix. It’s fair; organic matter is usually great for plants and simple to use. However, most people don’t realize it’s merely an ingredient.

   Strictly using potting mix is like attempting to make a loaf of bread out of only flour. All those bags of other materials on the shelves are also components for a successful plant diet!

  Potting mix is a great base material, however, alone it presents risks of compacting, becoming waterlogged, can mold easily, and over time will become depleted of nutrients. Consider mixing the following ingredients into your pots, ground and raised beds to meet your plant’s required nutrients, pH level, and volume of moisture.

🖱️Use our Plant Finder to find some details on your plant! We try our best to keep this updated!

👍 Rule of Green Thumb: Plant roots can help you to determine the medium needed – thick, robust roots (i.e., yucca) typically enjoy chunkier materials, and smaller, delicate roots (i.e., begonias) enjoy finer materials.

Mulch and Bark Bites

• Mulch is the organic slow-release fertilizer, as it slowly decomposes, it lowers soil pH. However, may eventually compact soil once fully broken down.
• In the meantime, it creates shelves in the soil that create air pockets and prevent the soil from compacting. Mulch is a great short term medium for arid potted plants.
• If kept too wet, it can harbour fungus gnat larvae.
• Make sure when sourcing your mulch it doesn’t contain any black walnut.

🖱️ See more on mulching here. 

Sphagnum Peat Moss

• Peat moss is used to help retain moisture and lower pH in the soil given it is harvested from bogs.
• Retains nutrients very well.
• It is difficult to rehydrate once it loses moisture.

Coconut Coir

• Coco coir, much like peat moss is used to keep the soil moist and keep pH low, however it lasts longer and is possibly less invasive to harvest.

Sand

• Grains are relatively large and do not bind, allowing for excellent drainage depending on grade.
• Adds weight to top heavy plants.
• Has no ability to store minerals itself, however, pH can vary by its content of shells, minerals like silica, or fine organic matter.

Manure & Compost

• Source these organic by products locally and ensure they’re not too hot. These additions can significantly lower pH.
• Sheep manure is usually near free of weed seeds as sheep digest seeds better than cattle and horses!

Perlite

• Perlite is a volcanic byproduct (so it floats like pumice) that helps drainage in the soil and prevents compaction – vital in the case of starting seeds.
• If a rockier, well-draining medium is required for your plant, consider perlite.
• Perlite can expand holding trace amounts of water.
• Perlite has a neutral, slightly acidic pH.
• Make sure when sourcing perlite, that you are not being sold Styrofoam balls.

Vermiculite

• Vermiculite is a recycled mineral used similarly to perlite, and too has a neutral, slightly acidic pH.
• Expands with water content.
• Can contain amounts of potassium and magnesium (as well as good cation exchange capacity).
• Runs the potential risk of introducing asbestos into your soil.

Calcined Clay Materials

• Clay materials like recycled brick bits, pottery, or lecca are typically used for arid plants as it improves aeration and drainage.
• Can raise pH.
• Can retain some water.
• High cation exchange.
• Can also be used for starting robust cuttings when kept moist.  
• Probably not ideal for inground amendments.

Maintaining Your Plant’s Dietary Needs

Perhaps we’ve crafted the perfect soil type for your plant – your plant thanks you – but over time, we will end up in the same staling predicament. Why? Because with each thorough watering, we leech the soil of the provided nutrients. Best we use the plant-specific required fertilizer for your plant to prevent nutrient loss.

   Organic sources of fertilizer such as bonemeal, composts, and manures, along with the application of lime, will improve the physical condition of the soil in terms of water and element holding ability. Unfortunately, in many cases though, manures and lime alone cannot be depended upon to provide enough available nutrients in soils with low essential element reserves.

   Let’s talk about commercial fertilizers, which can help target your plant’s exact needs much like vitamins and supplements!

The Scoop on Fertilizers

Of the essential 16 elements your plant pulls from the soil, Nitrogen (N), Phosphorus (P), and Potassium (K) are the most critical for good plant growth. You’ll recognize the three numbers appearing on your commercial fertilizer labels known as the fertilizer analysis of the product, representing the percentage of each of the three "macronutrients" in the order of N, P & K.

Nitrogen (N) is necessary for green leafy or vegetative growth which is important in crops like corn, cabbage, and potatoes.

☝️ It is important to remember that you should not use a fertilizer which is high in nitrogen late in the summer on your perennials, as it may cause a boost of growth which will only freeze as the cold weather sets in. Also, too much nitrogen in the analysis could cause too much lush, leafy growth thus inhibiting the desired flowering aspect of a plant species.

Phosphorus (P) promotes the development of flowers, fruit and roots. Crops like tomatoes, cauliflower and garden flowers.

Potassium (K) boosts plant hardiness, stem strength, resistance to disease and drought which is important to all crops, but especially in potatoes, celery and rhubarb.

👍 Rule of Green Thumb: For foliage plants, provide them with shade and lots of nitrogen, and for flowering and fruiting plants, provide them with lots of sun and lots of phosphorus!

Amending Clay

Hello Haldimand and Eastern Norfolk!

   We’re presented with the challenge of compacted, often shallow and waterlogged clay, which proves difficult but not impossible.

   Clay becomes compacted and waterlogged as it is the smallest soil particle – smaller than a grain of sand, and even smaller than silt – with rough edges that allow it to interlock and bind. In this instance, roots cannot penetrate further into the soil, are susceptible to root rot, and air pockets are slim to none.

   This, however, can be fixed with the addition and renewal of the above materials.

  Mindful that you don’t create a watery bowl in the ground (score the edges the area being worked), you can add organic matter (i.e., manure, compost, and potting soil) for nutrients, as well as mulch, sand and perlite for aeration and drainage. Annual soil particle aggregation in clay soils increases air porosity (air pockets) and is accomplished by the incorporation of organic matter that breaks down to form humus.

🖱️ See more here for planting trees in clay. 

We hope this soil and fertilizer guide helps you provide all the vital nutrients to your beloved plants in ground and above ground! For more information - and soil – visit Eising Greenhouse and Garden Centre! 🌱

While many gardeners in Southern Ontario follow the popular planting date of May 24th, when we’re usually safe from frost, you may be surprised to know that April is not too early for certain plants!

Once the ground has thawed and is workable, there’s plenty you can start growing. In Zones 6a-6b, this usually happens around four weeks before May 24th. While frost is still a possibility, many cold-tolerant plants not only survive a light frost but thrive in cooler weather. To check if the soil is ready, simply dig up a handful and squeeze it. If it sticks together, it’s too wet to work with—wait a few more days for it to dry out. Once the soil is ready, it’s time to plant those cool-weather crops!

Cool Weather Vegetables

Radishes: Radishes are fast-growing and perfect for planting in April because they love cooler weather. Sow them directly from seed.

Peas: April is the perfect time to plant peas outdoors as soon as the soil is workable. Soak pea seeds in water for 8-10 hours before planting them to help germination.

Lettuce, Spinach, Arugula, Asian Greens (Tatsoi, Mizuna, Pak Choi and Leaf Mustard) : It’s best to sow seeds for leafy greens or plant seedlings early in the spring as they will grow quickly in cool weather. Plant more seeds or seedlings every 10-14 days for a succession of greens until hotter temperatures make them bolt (go to seed) and become bitter.

Potatoes: Seed potatoes can be planted in mid to late April as soon as the soil is workable.

Onions: Plant onion sets or seedlings that have already been started in early spring and enjoy a harvest in late summer or fall.

Carrots: Plant carrot seeds in April, and they will be ready for harvest later in the spring or early summer. They take a little longer to grow, but planting early gives you a head start. You will enjoy carrots all summer long by planting more seeds a few weeks later.

Tip: It’s a good idea to keep some frost protection like row cover handy for lettuce, peas and spinach just in case the temperatures dip below zero.

Bonus: Many garden pests, like earwigs and slugs, are still overwintering in April and won’t feast on your tender plants.

Cold-Tolerant Flowers

Pansies: Add a pot of Pansies to cheer up a front porch, and it instantly feels like spring! Plants can go into a sunny spot in the ground when temperatures reach 7-21 celsius and are regularly staying above freezing.

Violas: These cool-weather flowers can withstand light frosts and are perfect for containers or for planting in garden beds

Gladiolas: Even though the weather is still cool, this resilient summer-blooming bulb can be planted in a sunny area of the garden in April. 

Bonus: Pansies and Violas also love cool weather in the fall.

Perennials, Trees and Shrubs

Two to three weeks before the threat of frost has passed, many potted perennials, shrubs and trees, either dormant or with leaves, can be planted. (If you’re not purchasing from us, be sure to check whether the plants were grown outdoors or acclimated to cooler temperatures and ensure they’re hardy enough for Southern Ontario.)

While perennials, trees, and shrubs can be planted throughout spring, summer, or fall, the combination of warming soil and increased rainfall in spring creates the perfect conditions for successful transplanting.

Come into Eising Garden Centre to see the many seeds and plants available for you to add to your garden in April!

Additional Resource: Landscape Ontario provides an excellent online Tree Planting Guide.