Site Assessment — Sun, Soil, Water, Space

Before you plant anything, assess your site systematically. The assessment determines what is realistic to grow.

Sun assessment

Most medicinal plants want full sun (6-8 hours of direct sunlight daily). Some tolerate partial sun (4-6 hours). A few prefer shade (2-4 hours direct sun or filtered light all day).

**Map your sunlight:**

For your potential garden area, observe at multiple times across one day. A spring or fall day is most useful (summer sun is longer; winter sun is shorter and lower-angle). Note:

- Hours of direct sunlight at each spot - When the sun arrives (morning, midday, afternoon) - When the sun leaves - Any shade from trees, structures, fences

Result: a rough sun map of your area. Areas with 8+ hours of direct sun support the widest range of medicinal plants; areas with less sun limit your options.

**Sun categories for medicinal plants:**

**Full sun (6-8+ hours):** - Most Asteraceae (calendula, echinacea, chamomile, yarrow) - Most Lamiaceae (mints will tolerate part shade, but most prefer sun) - Most root crops (valerian root, ashwagandha, marshmallow) - Most fruiting plants (hawthorn, elder) - Most aromatic plants where volatile oil content matters

**Part sun (4-6 hours):** - Lemon balm - Some mints - Lobelia - Comfrey - Some flowers

**Shade (2-4 hours or filtered light):** - Goldenseal - Black cohosh - Wild ginger - Ginseng (very specific shade conditions) - Some understory medicinals

If your site is mostly shaded, you'll be growing primarily shade-tolerant species. That's not a problem; it just shapes your plant selection.

Soil assessment

Medicinal plants generally prefer well-drained, moderately fertile soil. Specific patterns:

**Soil texture.** Sandy soils drain fast but don't hold nutrients well; clay soils hold nutrients but drain slowly; loam (a mix) is generally best.

To test texture: take a moist (not wet) handful of soil. Squeeze. Sandy soil falls apart immediately. Clay soil holds a tight ball. Loam holds a loose ball that crumbles easily.

**Drainage.** Many medicinal plants don't tolerate wet feet. Drainage test: dig a small hole (1-2 feet deep), fill with water, watch how fast it drains. Fast drainage (over within 1-2 hours) is good for most plants. Slow drainage (over 4-6 hours) requires raised beds or specific plant selection.

**pH.** Most medicinal plants prefer slightly acidic to neutral pH (6.0-7.0). Some prefer slightly alkaline (lavender). A few prefer more acidic (blueberries, though they're more food than medicine). A soil test from your extension office tells you pH; you can adjust with lime (raises pH) or sulfur (lowers pH).

**Fertility.** Medicinal plants generally don't need rich soil. Many do best in moderately fertile soil; some (calendula, nasturtium, some flowers) actually produce stronger medicinal compounds in nutrient-stressed conditions.

Water assessment

**Annual rainfall.** Your local weather records will show typical annual rainfall. Most medicinal plants need 25-40 inches per year. If you're in a dry climate (under 25"), supplemental irrigation will be needed.

**Distribution.** Rainfall distribution matters as much as total. Mediterranean climates (wet winter, dry summer) require different management than continental climates (rain throughout the growing season).

**Irrigation infrastructure.** If supplemental water is needed, do you have: - Spigot or hose access nearby? - Drip irrigation possibility? - Time to hand-water?

A garden too far from water source is difficult to maintain through dry periods.

Space assessment

**Total area.** Measure your potential growing space accurately. A rough sketch with dimensions helps planning.

**Bed shape and access.** Long narrow beds are easier to reach from both sides than wide ones. Beds wider than 4 feet are hard to reach the middle.

**Paths.** Plan paths between beds for access. Hard paths (mulch, gravel, stepping stones) prevent compaction.

**Storage and processing space.** Where will harvested plants dry? Where will you process tinctures, salves, etc.? An outdoor space with shade and good airflow for drying, plus indoor counter space for processing, is part of the apothecary infrastructure.

Microclimates

Within any given site, microclimates exist:

**South-facing slopes** are warmest and driest. Plants that want heat (lavender, sage, oregano) do well here.

**North-facing slopes** are coolest and moistest. Plants that want cooler conditions (mint, comfrey) do well.

**Near walls** are warmer than open areas in winter. Some marginally hardy plants (rosemary in cold climates) survive against south-facing walls.

**Low spots** collect cold air at night (frost pockets) and can be wet. Often unsuitable for many medicinal plants but good for moisture-lovers (marshmallow, water hyssop).

**Wind exposure** affects plants. Wind-exposed areas are colder in winter, drier in summer. Plant tougher species there; tender plants in sheltered spots.

The assessment summary

After your assessment, you should be able to answer:

1. How much full-sun growing space do I have? 2. How much part-sun growing space? 3. Is my soil well-drained? 4. What's my soil texture and pH? 5. How much rainfall do I typically receive? 6. Do I have supplemental irrigation capacity? 7. What microclimates exist on my site? 8. What's my realistic growing area in square feet? 9. What's my proximity to water source for irrigation? 10. Where will I do drying and processing?

These answers shape everything that follows.

What to carry forward

Complete the site assessment for your growing area. Document the answers to the 10 questions above. Sketch a rough map of your site showing sun, soil, microclimates, and proposed growing area.

Next lesson, the 30-plant core apothecary.