1. Container Gardening Part 2 Soil, Water, Nutrients, Light
This is first of 4 parts of the soils and fertilizers lectures. In this first part, we will learn about soil strcture.

2. Soils for Containers ‘Soilless’ Mixes
Container soil is challenging because of the small volume of media used to support plant growth
Desirable traits:
Water and nutrient retention
‘Soilless’ Mixes
Low bulk density (fluffy and light)
High porosity to ensure good aeration and root growth
Free from weeds, diseases, and insects
The potting soil, or medium in which a plant grows, should be porous for root aeration and drainage, but also capable of water and nutrient retention.
Don’t use garden soil, or soil from other areas of your yard to fill your containers. Garden soil is too heavy for container plants, and will not provide the aeration and drainage necessary for vigorous growth. Also, don’t use peat moss in your containers, as it is too acidic for most container plants, and does not retain water.
Instead, use a commercially prepared potting mix. Most commercially prepared mixes are termed ‘artificial’ or ‘soilless’.
These mixes contain a blend of Soilless growing mixes containing a blend of sphagnum peat, perlite, and vermiculite. You can up to 25% compost into these mixes, to add nutrients to the mix.
Soilless mixes are lightweight, which makes it easier to move containerized plants, which can be quite large, from location to location . This is a desirable trait, as you will probably have to move your containerized plants at least once per year in order to accommodate their abiotic needs through changing seasons. Soilless mixes are highly porous, which helps to ensure good aeration, and allows good root growth. In addition, soilless mixes and are free from soil-borne diseases, weed seeds and insects. Thus, soilless mixes lesson pest pressures on container-grown plants.

3. Soils for Containers
Organic Blend: 5 gallons finished compost, 1 gal. sand, 1 gal. vermiculite or perlite, and 1 cup granular all purpose organic fertilizer.
Standard Blend: 1 bushel vermiculite, 1 bushel ground spagnum moss, 8 tablespoons superphosphate (0-20-0), 8 tablespoons ground limestone, 2 cups bone meal.
Garden Soil: 25% sand, 25% garden soil, 50% compost.
You can also make your own potting soil. Listed on this slide are the recipes for an organic blend (which uses compost and organic fertilizer), and a standard blend potting soil (which uses both a synthetic fertilizer, as well as bone meal). You can find many, many more recipes online.
Note the high vermiculite or perlite content in both the organic and standard blends. Both vermiculite and perlite are lightweight aggregates, which impart the aeration and drainage so necessary in a good potting mixes. Compared to the garden soils – 1 part of potting mix will be MUCH lighter than 1 part of garden soil.
For more on soil blends for containers, please visit the External Links folder associated with this module. There, you will find a YouTube video on soil mixes for container plants.

4. Watering Container Plants
Increased water and nutrient needs
Thoroughly water once per week – twice per day
Water depending on container and weather
Cluster pots to minimize moisture loss
Water needs greatest at flowering and fruiting
Sedum mulch
Relative to non-containerized plants, container-grown plants generally require more water and nutrients. Thoroughly water your pots, until all the soil in the container is moist and water runs out the drainage holes. Use saucers or trays to catch excess water.
Do this once or twice each week. The specific frequency will depend on the container and the weather. Small containers require more frequent watering than large containers, and watering needs will increase in warmer weather.
You can decrease evaporation from large containers by using a thin layer of mulch. Or, you can use ground cover-type plants, like sedums, as a living mulch for your container plants. Clustering pots is another way to minimize moisture loss from containerized soils.
In addition, plants demand more water when flowering or fruiting. Thus, adjust your watering schedule accordingly.
Mulched plant

5. Watering Container Plants
Too much or too little water is the most common problem for container grown plants
Drip Irrigation Systems (below, left)
Self Watering Containers (below, right)
The most common problem with container gardens is too little or too much water. Because the volume of soil is relatively small, containers can dry out very quickly, especially on a concrete patio in full sun. Daily, or even twice daily watering may be necessary.
Learn to use your fingers to gauge the need for water, then apply enough to run through the drainage holes in the bottom of the container. This assures that the soil is thoroughly and uniformly wet and that excess salts are washed from the soil. On an upstairs balcony, this may mean neighbor problems, so make provisions for water drainage. However, DO NOT ALLOW THE POT TO SIT IN WATER. It will cause root damage because there will be no oxygen in the soil, and it will cause a build-up of salts that can be toxic to plants.
Drip Irrigation Systems or self-watering containers are two options you might want to consider – to manage the watering needs of your container plants.

6. Fertilizing Container Plants
Add slow-release fertilizer at planting such as Osmocote.
Initially, half-strength, water-soluble fertilizer
Increase fertilizer to recommended rate as plants mature
Occassionally use compost or fish emulsion for micronutrients
If you use a soil mix with fertilizer added, then your plants will have enough nutrients for eight to 10 weeks. Or, you can add a slow-release fertilizer to your soil mix, after your seeds germinate. After this time, you should add a water-soluble fertilizer, at half strength when the plants are young. You can gradually increase the fertilizer to the recommended rate, as your plants mature.
On average, Fertilizer your plants every two to three weeks. An occasional dose of fish emulsion or compost will add trace elements to the soil. Do not add more than the recommended rate of any fertilizer –since container plants are especially susceptible to fertilizer burn.

7. Light Possibly shade all day NORTH Morning sun, afternoon shade
Morning shade, afternoon sun
Morning sun, afternoon shade
WEST
EAST
SOUTH
Light conditions varies according to the cardinal direction of windows and other light-transmitting structures in your house. In general, east side windows will receive morning sun and afternoon shade. South-facing windows receive the most amount of sun each day. West-facing windows receive afternoon sun, and are shaded in the morning. North facing windows receive the least amount of sun each day.
Of course, adjacent buildings, trees and other structures may modify the specific light regime within your home – as will your use of curtains and other window coverings.
Possibly sun all day 7

8. Light Direct light – east or west windowsills, south-facing window
Bright, indirect light
Low light
Direct Light
Indirect Light
Low Light
Plants need light to grow, and light availability (or the lack thereof) can greatly influence your plant’s vigor. Indoors, you should place plants according to the light availability in your home, and the light needs of the plant.
Plants that need direct light should be placed on or near east- or west-facing windowsills that receive at least a few hours of direct sun during the day. Alternatively, you can place these plants up to a couple feet away from a south-facing window. Medicine plant, croton and ponytail palm do well in direct light.
Plants that do well in indirect light include Ficus, lady palm, and rubber plant. Place these plants where they will receive as much indirect light as possible. Potential locations are a few feet from a south- or west-facing window, or nearer a south or west facing window that with a sheer curtain screen.
Low light conditions characterize a north-facing window or the interior of a room. Plants that will grow well in low, indoor light include dracaenas and Chinese evergreen

9. Light Too much sun – trellis Too little sun – reflective wall or water
Outdoors, you can modify your plant’s light regime by selectively placing them in sunny or shady conditions. If you want to decrease the amount of sun your plants receive, you can place them beneath a trellis. If you would like to increase the amount of sunlight they receive, you can place them next to a reflective surface – such as a light-painted wall or a pond. 9