Select appropriate pots, ensure proper drainage, and choose soil mixes that support healthy root development. Container quality directly impacts herb growth and longevity.
Most culinary herbs need containers at least 15cm deep to develop healthy root systems. Basil, parsley, and cilantro thrive in 15-20cm pots, while rosemary and mint require 20-25cm depth for vigorous growth. Shallow containers restrict roots, leading to stunted plants and frequent watering. Choose width based on mature plant size: 10-15cm diameter for single herbs, 25-30cm for multiple plants.
Every herb container must have drainage holes to prevent root rot, the number one killer of indoor plants. Aim for one 1cm hole per 10cm of pot diameter. If using decorative containers without drainage, drill holes yourself or use them as cache pots with a functional inner pot. Excess water must escape freely, especially important in Canadian homes where humidity varies with heating and air conditioning cycles.
Terra cotta pots are porous, allowing soil to breathe and dry evenly, ideal for herbs prone to over-watering like rosemary and oregano. They're heavier and require more frequent watering. Plastic pots retain moisture longer, perfect for thirsty herbs like basil and mint, and they're lightweight for easy rearranging. In heated Canadian winter homes, terra cotta's breathability helps prevent fungal issues, while plastic conserves precious moisture.
Combine equal parts quality potting soil, perlite or vermiculite, and compost for an ideal herb-growing medium. This blend provides nutrients, excellent drainage, and moisture retention without compaction. Avoid garden soil, which is too dense for containers and may harbour pests. Pre-made potting mixes work well, but adding 20% perlite improves drainage. Refresh soil annually to maintain structure and fertility for sustained herb production.
Self-watering pots feature a reservoir that wicks moisture into the soil as needed, reducing watering frequency to once weekly or less. Perfect for busy Canadians who travel or work long hours, these systems prevent both over and under-watering. Choose models with water level indicators and drainage overflow. Basil, parsley, and chives excel in these containers, maintaining consistent moisture for rapid, healthy growth.
Contrary to popular belief, adding gravel or pottery shards at the pot bottom doesn't improve drainage and can actually create a perched water table. Instead, use quality well-draining soil and ensure adequate drainage holes. If using deep pots, fill extra space with upside-down nursery pots before adding soil to reduce weight and soil volume while maintaining proper depth for roots. Save your energy and materials for better purposes.
Place saucers under pots to protect windowsills and furniture from water damage, essential in Canadian homes with wooden surfaces. Empty saucers 15-30 minutes after watering to prevent root rot from standing water. Choose saucers 2-3cm larger than pot diameter to catch all drainage. Elevate pots on small feet or pebbles inside saucers to keep drainage holes clear and allow air circulation beneath containers.
Yogurt containers, takeout tubs, and coffee tins make excellent herb pots when drainage holes are added with a drill or heated nail. Ensure containers are thoroughly cleaned and at least 15cm deep. This sustainable approach reduces waste while saving money for beginner gardeners testing their green thumb. Paint or wrap upcycled containers in fabric or paper for aesthetic appeal while reducing plastic waste in Canadian landfills.
Repot herbs when roots circle the drainage holes or growth slows despite adequate care. Spring is ideal timing, though indoor herbs can be repotted anytime. Choose a container 5cm larger in diameter, refresh soil completely, and trim any dead roots with clean scissors. This rejuvenation extends plant life significantly. Mint and oregano particularly benefit from annual repotting as they grow vigorously and quickly deplete soil nutrients.
Most culinary herbs prefer slightly acidic to neutral soil with pH 6.0-7.0, which standard potting mixes naturally provide. There's no need to test or adjust pH for typical indoor herb gardens unless plants show persistent yellowing despite proper care. Canadian tap water tends to be neutral to slightly alkaline, which suits herbs well. Focus instead on good drainage and regular fertilizing for healthy, productive plants.