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Give Your Garden a Spring Check-Up: Focusing on Soil Health for a Bountiful Calgary Season!

It’s easy to get caught up in choosing the prettiest flowers or the most promising seedlings. But before you dig in, let’s talk about the unsung hero of your garden’s success: the soil beneath your feet.

Think of your soil as the foundation of your entire gardening endeavor. It’s not just dirt; it’s a living, breathing ecosystem that provides essential nutrients, water, and support for your plants. Giving your soil a little TLC now can make a world of difference in the health, resilience, and productivity of your garden all season long. 

The Crucial Balancing Act: Understanding Soil pH

One of the first things to consider when assessing your soil health is its pH level. You might remember this from high school science class, but trust us, it’s incredibly relevant to your gardening success. pH is a measure of how acidic or alkaline your soil is, on a scale of 0 to 14. For most plants, the sweet spot lies between 6.0 and 7.0, which is considered neutral to slightly acidic.

Why is pH so important? Well, it directly affects how your plants access nutrients in the soil. Imagine your soil is a well-stocked pantry, full of all the vitamins and minerals your plants need. But if the pH is off, the doors to some of those essential nutrients might be locked shut!

• Too acidic (low pH): When the soil is too acidic, certain elements like aluminum and manganese can become overly soluble. While plants need trace amounts of these, too much can be toxic, potentially burning delicate root tips. Moreover, the availability of crucial nutrients like phosphorus and molybdenum can be reduced. Interestingly, certain fungal diseases like Fusarium wilt and root rot tend to thrive in acidic conditions.
• Too alkaline (high pH): On the other end of the spectrum, alkaline soil can make it difficult for plants to absorb vital nutrients like iron, manganese, and phosphorus, even if they are present in the soil. This can lead to nutrient deficiencies and stunted growth. Plus, soil microbes, which are essential for breaking down organic matter and cycling nutrients, can be hampered in highly alkaline conditions. Scab, a common plant disease in potatoes, also tends to flourish in alkaline soil.

Plants have pH preferences. For instance, if you’re dreaming of a bountiful blueberry harvest, you’ll need more acidic soil (around 4.5 – 5.5). On the other hand, fragrant lavender and beautiful lilacs prefer slightly alkaline conditions (6.5 – 8.0 and 6.5 – 7.5 respectively). Knowing your plants’ needs is key! Ask us if you’re unsure!

What can you do if your pH is off?

• To raise pH (reduce acidity): Incorporate dolomitic lime into your soil. This natural amendment slowly releases calcium and magnesium carbonates, which neutralize acidity.
• To lower pH (increase acidity): You can use aluminum sulfate to make your soil more acidic. Be sure to follow application instructions carefully, as overdoing it can harm your plants.

You can purchase simple soil pH test kits at our garden centre to get an accurate reading of your soil’s current pH.

The Often-Overlooked Factor: Soil Temperature

While we Calgarians are well-versed in fluctuating air temperatures, soil temperature is another crucial factor that often gets overlooked. Just like us, plants and soil organisms have a preferred temperature range for optimal activity. Generally, a soil temperature between 15 and 25 degrees Celsius is ideal for most garden plants.

Why does soil temperature matter?

• Germination: Seeds require a certain soil temperature to sprout successfully. Too cold, and they might not germinate at all. Too hot, and they could be damaged.
• Root Growth: Roots grow best within the optimal temperature range, allowing them to efficiently absorb water and nutrients.
• Moisture Uptake: Soil temperature influences the rate of evaporation and transpiration, affecting how much water your plants need.
• Microbial Activity: Those beneficial bacteria and fungi we mentioned earlier are also sensitive to temperature. The ideal range encourages their activity in breaking down organic matter and making nutrients available.
• Plant Disease: Extreme soil temperatures can stress plants, making them more susceptible to diseases.
• Nutrient Activity: Soil temperature affects the rate of chemical reactions that release nutrients in the soil.
• Overall Health and Productivity: When the soil temperature is just right, your plants are generally healthier, more vigorous, and more productive.

Think about which areas of your garden tend to warm up faster. South-facing beds in full sun will naturally have warmer soil than shady, north-facing spots. This is why certain plants thrive in “hot soil zones” like peppers, tomatoes, cucumbers, beans, basil, rosemary, thyme, lavender, zinnias, echinacea, and rudbeckia, while others prefer “cool soil zones” such as leafy greens, peas, root vegetables, broccoli, cauliflower, cabbage, sage, dill, and chives.

While sunlight and shade are the primary drivers of soil temperature, there can be exceptions. For example, impatiens prefer shade but also appreciate warmer soil.

Directly measuring soil temperature without a soil thermometer can be tricky. Observing how quickly your soil dries out and noting the general microclimate of different areas in your garden can give you some clues. Mulching can also help regulate soil temperature, keeping it cooler in the summer and slightly warmer in the spring and fall.

Power Up Your Patch: The Importance of Soil Amendments

Let’s move on to how we can actively improve our soil health through amendments. Think of amendments as adding beneficial ingredients to your soil “recipe.”

Here are some of the big hitters when it comes to soil amendments:

• Compost, Manure, Worm Castings, Peat Moss, and Coir: These are your foundational organic amendments. Adding organic matter to your soil is one of the best things you can do for its overall health. They improve soil structure, enhance water retention and drainage, provide a slow-release source of nutrients, and boost beneficial microbial activity. Each has its own unique benefits:
  • Compost: A fantastic all-around amendment made from decomposed organic materials.
  • Manure: Rich in nutrients, but be sure to use well-rotted manure to avoid burning plants.
  • Worm Castings: Often called “black gold,” these are the nutrient-rich byproduct of earthworms.
  • Peat Moss: Excellent for improving water retention and aeration in heavy soils, but consider its environmental impact and explore sustainable alternatives like coir.
  • Coir: Made from coconut husks, coir is a sustainable alternative to peat moss with excellent water retention and drainage properties.

Beyond these core organic amendments, several other materials can provide specific benefits:

• Volcanic Minerals (e.g., rock dust): These slow-release sources of micro and macronutrients also help improve soil structure and enhance microbial activity. The silica content can even help strengthen plant cell walls, making them more resistant to pests and diseases.
• Epsom Salts (Magnesium Sulfate): A readily available source of magnesium, a crucial component of chlorophyll and essential for photosynthesis. A magnesium deficiency can lead to yellowing leaves.
• Iron: Adding iron can help “green up” plants by aiding in chlorophyll production, as well as supporting gas exchange and nutrient uptake. Iron deficiencies can also cause yellowing, particularly in younger leaves.
• Biochar: This charcoal-like material is fantastic for improving water and nutrient retention, boosting microbial activity, aiding in pH balance, increasing aeration and drainage, and even sequestering carbon in the soil.
• Dolomitic Lime: As mentioned earlier, this raises soil pH and reduces acidity while also providing calcium and magnesium.
• Aluminum Sulfate: Also discussed earlier, this lowers soil pH and increases acidity.
• Gypsum (Calcium Sulfate): Particularly beneficial for breaking up heavy clay soils. The calcium helps to displace sodium ions that bind clay particles together, improving soil structure and drainage.

Actionable Advice for a Healthy Start:

1. Test Your Soil pH: Pick up a simple soil pH test kit from our garden centre and get a baseline reading of your garden beds. This will help you understand if any adjustments are needed.
2. Incorporate Organic Matter: Before planting, amend your soil generously with compost, well-rotted manure, or worm castings. This will improve its structure, fertility, and water-holding capacity.
3. Consider Your Plants’ Needs: Research the specific soil pH and temperature preferences of the plants you intend to grow and choose amendments accordingly.
4. Mulch Wisely: Apply a layer of organic mulch around your plants to help regulate soil temperature, retain moisture, and suppress weeds.
5. Observe Your Plants: Pay attention to the health and growth of your plants. Yellowing leaves, stunted growth, or susceptibility to diseases can be signs of underlying soil issues.

Investing a little time and effort into understanding and improving your soil health now will pay dividends throughout the entire growing season. Healthy soil means healthier, more vibrant plants, bigger harvests, and a more rewarding gardening experience. So, come visit us at the garden centre, and let our knowledgeable team help you choose the right tools and amendments to give your Calgary garden the strong foundation it deserves! Happy gardening!