By July, gardens in the Boise area are alive with activity. Tomato vines climb their cages, squash leaves stretch across beds, and pollinators hum from blossom to blossom. But while the season’s early work is behind us, another critical task emerges: feeding the garden.
Plants are living systems, constantly drawing nutrients from the soil to fuel growth, flowering, and fruiting. As those nutrients are used up, the soil alone often can’t keep up with the demand—especially in raised beds, containers, or sandy soils common in southern Idaho. Understanding how to fertilize makes all the difference.
This guide walks through the most common fertilizing methods home gardeners use, when and why they matter, and how to apply them effectively.
Side-Dressing: A Midsummer Nutrient Boost
Side-dressing is the practice of applying fertilizer in a narrow band a few inches away from the base of a plant and watering it in. It's especially useful in July for long-season, heavy-feeding crops like tomatoes, peppers, squash, and corn.In early summer, nitrogen-rich materials (like urea, blood meal, or calcium nitrate) can support foliage development. But by midseason, as plants begin flowering and fruiting, excessive nitrogen can cause more leaf growth at the expense of blooms and harvest.
In July, a better choice is a balanced fertilizer (e.g., 5-10-10) or one higher in phosphorus and potassium to support flowering and fruit development. Organic options include composted manure, bone meal (typically 3-15-0), or natural blends formulated for tomatoes or vegetables.
Fertilizer should be applied 4–6 inches from the stem and gently worked into the soil or covered with mulch. Always water thoroughly after applying.
Top-Dressing: Slow and Gentle
Top-dressing is the process of applying compost or granular fertilizer to the soil surface around plants. It requires no digging and is ideal for leafy greens, herbs, root crops, and perennials—or anywhere you want to avoid disturbing roots.
This method supports soil structure, boosts moisture retention, and releases nutrients slowly. It’s especially well suited for use with compost or slow-release organic fertilizers. Mulching after top-dressing can further improve moisture retention and soil health.
Top-dressing can be repeated every few weeks throughout the growing season, especially after heavy rains or heat waves.
Liquid Feeding: Fast and Effective
Liquid fertilizers are mixed with water and poured around the base of the plant. This method is particularly effective in July when container-grown plants and raised beds may need quicker nutrient access due to faster drying and leaching.
Liquid soil drenches can be made from fish emulsion, compost tea, kelp extract, or water-soluble commercial fertilizers. Apply every 1–2 weeks as needed.
This method is fast-acting and easy to tailor, especially for vegetables like cucumbers, squash, or tomatoes that show nutrient stress mid-season.
Foliar Feeding: Targeted and Temporary
Foliar feeding involves spraying a diluted fertilizer solution directly onto plant leaves. It’s sometimes used to address visible nutrient deficiencies or to support plants under short-term stress.While plants can absorb some nutrients through their leaves—especially micronutrients like iron, magnesium, or calcium—this method is usually most effective as a supplement, not a replacement for soil fertilization. Effectiveness depends on nutrient type, leaf age, and weather conditions.
Foliar sprays may help:
- Correct specific deficiencies quickly
- Support stressed or struggling plants
- Bypass root-zone issues temporarily
However, they can also:
- Burn leaves if applied in hot, dry weather
- Offer only short-term results
- Increase disease or runoff risk if overused
Apply foliar sprays only when clearly needed, and always during cooler parts of the day—morning or evening. For most gardens, foliar feeding plays a limited, supportive role, best reserved for micronutrient issues or recovery from stress.
Pre-Plant Incorporation: Building the Foundation
Though not a July task, it’s worth noting that much of a garden’s nutrient supply should be in place before planting. Mixing compost and a balanced fertilizer into beds in early spring provides a steady source of nutrients as plants establish.
This early step is especially important for root development and early vegetative growth. Soil testing can help fine-tune what’s needed.
Summary Table
Method |
Best Use |
Midseason (July) Application |
Side-Dressing |
Fruiting vegetables |
Use balanced or low-nitrogen blends |
Top-Dressing |
Leafy greens, herbs, perennials |
Apply compost or slow-release fertilizer |
Liquid Feeding |
Containers, raised beds |
Every 1–2 weeks with water |
Foliar Feeding |
Nutrient deficiencies, stress |
Use selectively; best for micronutrients |
Pre-Plant Mix |
All crops |
Done at planting; provides base nutrition |
Final Thoughts
Fertilizing in July is about balance. The garden is in full gear, and plants need support—but not too much. Focus on what your soil and plants are telling you. Look for signs of deficiency, evaluate past applications, and use the right method for the right crop at the right time.
Fertilizing smart in midsummer can mean the difference between a sluggish garden and a bountiful harvest.
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