Know Your Plants' Needs

Vegetables and
Annual Flowers

Class 1: Gardening Basics
Class 2: Garden Planning & Design
Class 3: Indoor Seed Starting
Class 4: Planting & Transplanting
Class 5: Maintaining a Healthy Garden
Class 6: Troubleshooting

Just like we humans need certain things to survive -- for example, water, food, and shelter -- plants also have some basic needs. At a minimum, all green plants need light, air, water, and mineral nutrients. We'll be referring to these basic needs throughout this course, because most gardening tasks relate directly or indirectly to filling one or more of these needs.

As a gardener, your job is to ensure that your plants' needs for light, air, water, and mineral nutrients are met.

Why do plants need these things, and how do they use them? Let’s take a brief look at how plants work.

Photosynthesis
All animals, including humans, must eat food to supply their bodies with energy. Plants, on the other hand, have the remarkable ability to manufacture their own food. Plants "harvest" the energy of the sun, then use this energy to manufacture sugars. This process is called photosynthesis.

In addition to sunlight, plants need water and air to perform photosynthesis. They use mineral nutrients, the fourth basic need, to build the necessary cell structures.

Water
Plants also need water for things besides photosynthesis. They need water to maintain cell pressure -- and pressure within the plant's cells is what keeps stems sturdy and leaves opened to the sunlight.

Plants lose lots of water during the process of transpiration, during which water vapor escapes from pores on the undersides of the leaves. Why should gardeners care about transpiration? Because one of the most important factors in growing healthy plants is maintaining proper moisture levels. The rate at which a plant is transpiring has a huge effect on how much water it needs.

It may be frustrating for novice gardeners to hear the advice, "Keep the soil evenly moist," rather than, "Apply 2 cups of water per day," but a plant's water needs depend on soil type, as well as on environmental factors that can vary considerably from day to day and place to place.

The warmer, drier, windier, and sunnier it is, the more water a plant loses to transpiration. During dry weather, you need to replace this lost water, or plants will wilt.

Now let’s get down on our hands and knees and take a close look at the foundation of our gardens: the soil.

Class 1, Page 1 2 3 4 5 6 7

Children are drawn to the wonders of nature, but they are often influenced by our fears and prejudices.

Worms, toads, spiders -- children become afraid of these creatures only when we, as adults, react with fear or disgust.

Even if you aren't comfortable touching worms and spiders, encourage your children to be curious about nature. After all, each of these creatures is an ally to us gardeners!

(Of course, teach your children about any truly harmful creatures that inhabit your region, for example, poisonous types of spiders and snakes.)

Welcome spiders, such as this argiope, into your garden; spiders consume many pest insects.