Alpine and rock gardening

• A. South-facing
• B. North-facing ✓
• C. East-facing
• D. West-facing

Why: In the Northern Hemisphere, north-facing slopes receive the least direct sunlight, so they stay cooler and retain moisture longer, which suits many alpine plants.

• A. Waterlogged clay that holds moisture year-round
• B. Free-draining soil that does not stay wet around the crowns of plants ✓
• C. Deep, rich loam with high organic content
• D. Standing water collecting in a shallow depression

Why: Most alpine plants evolved on well-drained mountain soils and are prone to rot if their crowns sit in wet, soggy ground, especially in winter.

• A. Rocks absorb and radiate heat, and most alpine plants need full sun to flower well and stay compact ✓
• B. Shade causes rocks to crack in cold weather
• C. Alpine plants grow best under dense tree canopy
• D. Deep shade encourages the formation of heavy, lush foliage

Why: Alpine plants typically need strong light for compact growth and abundant flowering, and sun-warmed rock helps create the conditions they experienced in their native habitats.

• A. Adding a thick layer of peat moss over the surface only
• B. Creating a raised bed or mound and mixing in grit or gravel to improve drainage ✓
• C. Watering the area heavily to loosen the clay
• D. Leaving the soil untouched and planting directly into it

Why: Raised beds and added grit or gravel improve drainage in clay soils, helping to prevent the waterlogging that alpine plants cannot tolerate.

• A. The shaded lawn corner, because alpines enjoy dim light and moist soil
• B. The sunny sloping spot, because slope and sun improve drainage and provide the light alpines need ✓
• C. Either site works equally well, since alpines tolerate any conditions
• D. The flat corner, because level ground is easiest to plant on

Why: A sunny slope offers excellent drainage and ample light, both of which are essential for most alpine plants, while shaded, flat, poorly drained ground often leads to rot and weak growth.

• A. They prefer nutrient-rich soil that holds large amounts of water
• B. Their roots and crowns are prone to rot when left in wet, poorly drained conditions ✓
• C. Gritty soil raises the soil pH to a level that alpines require
• D. Fast-draining soil keeps the roots warm throughout the winter months

Why: Many alpine plants evolved on rocky slopes where water runs off quickly. Waterlogged soil around the crown and roots, especially in winter, leads to rot, so a gritty mix keeps excess moisture from pooling.

• A. Peat moss
• B. Coarse horticultural grit or sharp sand ✓
• C. Fresh compost
• D. Vermiculite

Why: Coarse horticultural grit or sharp (angular) sand opens up the soil structure and improves drainage. Peat and compost retain moisture, which is generally the opposite of what alpines need.

• A. Filling the bottom third with a layer of rubble, gravel, or broken crockery for drainage ✓
• B. Sealing the drainage holes with waterproof tape
• C. Packing the bottom with wet clay to hold moisture
• D. Covering the surface with a thick layer of mulch

Why: Adding a rubble or gravel layer at the base of a container or bed creates a reservoir that keeps the root zone above standing water, improving drainage. Sealing drainage holes or adding clay would trap water and increase rot risk.

• A. To attract beneficial insects that feed on pests
• B. To keep the crown dry, reduce rot, and protect the stems from soil splashing ✓
• C. To increase the nitrogen content near the roots
• D. To prevent seeds from germinating in the bed

Why: A layer of fine grit around the crown keeps the plant's base dry, reduces the risk of rot and fungal disease, and helps prevent soil from splashing onto leaves during rain.

• A. The plant produces abundant flowers each spring
• B. Water sits on the surface or the soil stays soggy for long periods after rain ✓
• C. The leaves develop a silvery, fuzzy texture
• D. The soil cracks slightly as it dries out

Why: Standing water on the surface or persistently soggy soil after rain indicates poor drainage. Left uncorrected, this often leads to root and crown rot in alpine plants.

• A. Standing the rock upright with its longest dimension vertical
• B. Burying roughly one-third of the rock below soil level with its natural strata running horizontally ✓
• C. Laying the rock flat on the soil surface so the top is level
• D. Setting the rock with its largest flat face pointing downward into the soil

Why: Natural rock is part of the earth's structure, so partially burying stone (about a third) and keeping its bedding planes or strata horizontal makes the feature look like a geological outcrop rather than an object placed on the surface.

• A. To add nutrients that alpine plants need to grow
• B. To improve drainage and keep the crowns of plants dry, reducing rot
• C. To retain moisture so the soil never dries out
• D. To raise the soil temperature in cold climates

• A. Smooth, rounded river cobbles collected from a streambed
• B. Locally sourced stone that matches the surrounding native geology ✓
• C. Brightly colored decorative stone imported from another continent
• D. Polished granite slabs cut into uniform squares

Why: Locally sourced stone that matches the native geology blends into the landscape and looks authentic, whereas imported or uniformly cut stone looks artificial and clashes with the surroundings.

• A. Odd numbers are easier to count when purchasing stone
• B. Irregular groupings look more natural and avoid a rigid, manufactured appearance
• C. Plants grow better when placed between an odd number of rocks
• D. Odd-numbered groups reduce the weight load on the soil

• A. Directly on top of the rocks where they receive the most sun
• B. In pockets and crevices between rocks and at the base, where soil and moisture accumulate
• C. In a straight row along the front edge of the rock garden
• D. Only on the north side of each rock to shield them from light

• A. The color of the flowers
• B. Matching the plant's hardiness zone and climate tolerance to your local conditions ✓
• C. The price of the nursery stock
• D. How quickly the plant grows indoors

Why: Alpine plants are adapted to specific temperature, moisture, and light conditions. Matching their hardiness zone and climate tolerance to your region is the best predictor of long-term success.

• A. They need constant shade to survive
• B. They evolved in cool mountain conditions and often rot when summer heat and humidity combine with poor drainage ✓
• C. They require high nitrogen fertilizer to tolerate heat
• D. They are naturally drought-resistant and therefore die in humidity

Why: Alpine plants typically grow in cool, bright environments with sharp drainage. Heat and humidity together increase fungal disease and root rot, especially where soil stays wet.

• A. The average annual rainfall of a region
• B. The average annual minimum winter temperature, helping gardeners choose plants likely to survive winter ✓
• C. The soil pH range of a region
• D. The number of frost-free days for vegetable planting only

Why: USDA hardiness zones are based on average annual extreme minimum temperatures, giving gardeners a guideline for which perennial plants can survive winter outdoors.

• A. Deep, rich, moisture-retentive clay soil
• B. Excellent drainage, often achieved with gritty or rocky soil mixes ✓
• C. Constant waterlogged conditions
• D. Heavy shade under dense tree canopy

Why: Alpine plants grow on rocky slopes where water drains quickly. Gritty, well-drained soil keeps roots from sitting in moisture, which is a common cause of failure.

• A. Choose only plants from tropical regions
• B. Select cold-adapted species that tolerate heat, provide afternoon shade, and create raised or gritty planting areas ✓
• C. Water alpine plants heavily every day in summer
• D. Plant them in the deepest, darkest part of the yard

Why: Warm-climate gardeners can succeed by choosing the more heat-tolerant alpine species, shading plants from hot afternoon sun, and improving drainage through raised beds or gritty mixes.

• A. Heavy clay that holds moisture year-round
• B. Sharp drainage that prevents waterlogging around the roots ✓
• C. Rich, dark compost with high nitrogen content
• D. Peat-based mix that stays constantly wet

Why: Most alpine species evolved on slopes where snowmelt and rain drain quickly. Waterlogged roots, especially over winter, are a leading cause of failure, so sharp drainage is essential.

• A. Midsummer, when the soil is warmest
• B. Late autumn just before the ground freezes hard
• C. Early spring during active growth, or early autumn while soil is still warm ✓
• D. Mid-winter, when plants are dormant

Why: Planting in spring or early autumn gives roots time to establish before stress periods. Midsummer heat and deep winter cold both stress new plantings, which have not yet built root systems.

• A. To make them easier to water from above
• B. To prevent crown rot by keeping the base of the plant dry ✓
• C. To increase the amount of sunlight reaching the leaves
• D. To allow the roots to spread upward

Why: Many alpines are prone to rotting at the crown when moisture sits around the stem. Raising the crown slightly, often with a gravel mulch, keeps the vulnerable base drier.

• A. To add nutrients directly to the root zone
• B. To suppress weeds and keep the crown and leaves dry and clean ✓
• C. To raise soil acidity for heather-type species
• D. To attract beneficial insects to the plant

Why: A gravel top dressing keeps water from splashing up onto leaves and stems, reduces rot, discourages weeds, and mimics the stony conditions alpines naturally grow in.

• A. Heavy fertilizing every two weeks
• B. Regular, careful watering until roots are established, while avoiding soggy conditions ✓
• C. Pruning back all foliage to encourage bushy growth
• D. Covering the plant with plastic to retain humidity

Why: New alpines need consistent moisture while roots establish, but overwatering or poor drainage can kill them. Fertilizing and pruning can stress young plants, and plastic covers trap damp air that promotes rot.

• A. Gritty soil retains more moisture for the roots to absorb
• B. Sharp drainage prevents roots from sitting in wet conditions that cause rot ✓
• C. Grit adds nitrogen that alpine plants need in large quantities
• D. Gritty soil warms up faster in spring, forcing early flowering

Why: Most alpine plants evolved on steep, rocky slopes where water drains rapidly. Waterlogged roots, especially in cold months, are a leading cause of rot, so a gritty mix with added grit or stone chippings keeps the crown and roots from staying wet.

• A. Every evening during the summer heat
• B. Only during dry spells, allowing the soil to dry between waterings ✓
• C. Daily during winter to keep the roots hydrated
• D. Only when the plants visibly wilt in the afternoon

Why: Established alpines are generally drought tolerant and suffer more from overwatering than underwatering. Watering deeply during dry periods and letting the soil dry out between sessions encourages strong, deep roots and reduces rot risk.

• A. A high-nitrogen lawn fertilizer applied monthly
• B. A rich, well-rotted manure mixed into the planting pocket
• C. A low-nitrogen, slow-release or lightly applied balanced feed ✓
• D. Heavy doses of bone meal every week

Why: Alpines grow in nutrient-poor conditions, and excess nitrogen produces lush, weak growth that is more vulnerable to frost and disease. A light, low-nitrogen feed applied sparingly suits their compact, sturdy habit.

• A. To insulate the roots from frost while keeping the crown dry ✓
• B. To hold moisture around the plant during freezing weather
• C. To provide extra nutrients as the stone slowly breaks down
• D. To attract beneficial insects that protect the plant

Why: A gritty mulch keeps water from pooling around the crown, which is where rot most often starts. It also helps stabilise soil temperature and reduces damage from freeze-thaw cycles that can heave plants out of the ground.

• A. Wet soil freezes more quickly, cracking the root system
• B. Cold wet conditions cause roots and crowns to rot, while many alpines tolerate low temperatures well when dry ✓
• C. Moisture washes away the nutrients the plant stored in autumn
• D. Wet foliage attracts snow mould that kills the plant within hours

Why: Many alpines are highly cold-hardy when their roots stay dry, since they naturally grow under snow cover or on exposed slopes. The combination of cold and saturated soil, however, leads to rot, which is why winter drainage and protection from excess rain matter so much.

• A. Hardwood stem cuttings taken in late autumn
• B. Softwood or semi-ripe cuttings taken in early summer ✓
• C. Grafting onto rootstock of a related alpine species
• D. Layering of mature woody branches

Why: Many cushion and mat-forming alpines root readily from short, non-flowering shoot tips taken in early summer, when the tissue is actively growing but not yet woody. Hardwood cuttings, grafting, and layering are rarely used for these low-growing plants.

• A. To add nutrients for rapid early growth
• B. To retain moisture so seeds germinate quickly in summer
• C. To provide drainage and prevent seeds and seedlings from rotting ✓
• D. To shade young seedlings from intense mountain sunlight

Why: Alpine plants evolved in free-draining, mineral-rich soils, and seeds and young seedlings are highly susceptible to damping-off and rot in wet, organic media. A gritty mix mimics those conditions and keeps the surface drained.

• A. It stops the plant from producing new shoots
• B. It keeps the crown and foliage dry and reduces rot, especially in winter ✓
• C. It raises the soil pH to a more alkaline level
• D. It prevents all weed seeds from ever germinating

Why: A grit top-dressing keeps the crown of the plant and the surrounding soil from staying waterlogged, which is the most common cause of winter losses in alpines. It also helps moisture drain away from the neck of the plant.

• A. At the peak of flowering in midsummer
• B. During early spring as new growth begins, or in early autumn ✓
• C. In the middle of winter when the ground is frozen
• D. Immediately after a heavy rainfall

Why: Dividing in early spring or early autumn allows the divisions to establish roots while conditions are cool and moist, without the stress of peak heat or the risk of frost heaving in deep winter. Dividing during flowering diverts energy the plant needs for blooms.

• A. Watering heavily every day throughout the summer
• B. Applying high-nitrogen fertiliser each spring
• C. Regularly removing encroaching weeds and trimming aggressive spreaders ✓
• D. Covering the entire bed with mulch made of peat

Why: Rock gardens rely on the careful balance of small plants, and vigorous spreaders or weeds can quickly swamp slow-growing alpines. Regular weeding and trimming back of aggressive plants keeps the planting composition intact, whereas heavy watering or high nitrogen would encourage the wrong kind of lush growth.