Propagating plants from seed is relatively simple and saving seed from your harvest can be an easy and inexpensive way to grow more of your favorite flowers and food.

Mature butterfly weed seeds are dry and ready to save or sow.
PC: Leslie F. Halleck

When you have plants growing in your garden that you want to save seed from, you'll want to allow the seed to mature and dry completely on the plant. Some plants, such as the Asclepias (milkweed) you see in the photo, have obvious seed pods that will dry and turn a brown color when the seeds are ready. Asclepias pods will start to pop up when the seeds are ready to disperse.

You can cut off the entire seed pod and store them, or remove the seeds from the pod and store them. Always store seeds in a cool dry place in containers that won't retain any moisture.

You can learn much more about starting and saving seeds in my book Plant Parenting

Are you a new plant parent? Many plants, such as these assorted tropical houseplants and herbs below, can be propagated simply by taking cuttings from the plant and rooting them in water.

PC: Leslie F. Halleck

Depending on the type of plants and their natural environment, plants typically fall into two propagation groups: seeds and vegetative cuttings (also called cloning). Some plants are more easily propagated by seed, and others by cuttings. Some plants are easily propagated using both methods.

Not all plants root well in water - it's a race to root before they rot! So you'll find that you can have easy success water rooting many fleshy tropicals, but semi-woody or woody cuttings can be more difficult. Make sure to keep the water clean - change it if it starts to get cloudy. You can use any clear vessel of any color to root your cuttings.

To learn more about water rooting and all forms of plant propagation, get my new book Plant Parenting

Not all plants can be propagated the same way or under the same growing conditions. If you’ve struggled to get your succulents to root before they rot or can’t seem to get your lettuce seed to germinate, I'm going to get you on the right track with my new book Plant Parenting: Easy Ways to Make More Houseplants, Vegetables, and Flowers.

PC: Leslie F. Halleck

Plants use a variety of reproductive strategies. Some plants multiply most easily via seeds. Some plants are also easily propagated by taking vegetative cuttings. Some plants do it all! In the photo you can see an African violet leaf petiole cutting, aeonium tip stem cutting, and an avocado seed, each rooting in water.

Learn more in my new book Plant Parenting

The measurement of lumens tells you how much light you can expect to see from a given lamp, or the total amount of light output. Lumens per watt (LPW) is used to measure the efficiency of a lamp, or how much electricity a lamp converts into light versus heat.

Remember, plants and people see and use light differently. A light source may seem bright to your eye, but that doesn’t mean it’s better for plants.

Gardening Under Lights Book

When grown outdoors, peppers are a tough and pest resistant crop. Not much likes to munch on pepper foliage or the hot fruit. However, once you grow peppers indoors you'll find there are some pests that can be an issue. Aphids are a common on new pepper plant foliage when grown indoors and on pepper seedlings you're growing indoors to plant outdoors. .

Aphids can be difficult to treat as they are persistent on indoor crops. Best methods for control include: sticky traps, horticultural oils, and spinosad sprays.

Gardening Under Lights Book

Are you growing tomatoes indoors, or growing them outdoors in a cool climate? Gardeners in cool climates often struggle to get tomatoes to ripen before temperatures get too cold.

Tomatoes grow well with daytime temperatures between 70°F and 90°F (21–32°C) and a drop night temperatures to between 55°F and 75°F (13–24°C). Night temperatures above 85°F (29°C) can cause heat delay, where plants don’t set fruit. Cooler temperatures will slow or stop ripening.

If you live in a warm climate, and planted fall tomatoes, you might also struggle to get them to ripen once night temperatures get too cool in fall.

If you're growing tomatoes in your outdoor garden, but just can't get them to ripen, you're going to need to warm it up! If you haven't figured out how to control the weather (slacker), then consider bringing the plants indoors, under grow lights, to provide warmer temperatures and fruit ripening.

New BOOK! Gardening Under Lights: The Complete Guide for Indoor Growers

You can fill your propagator with multiple types of cuttings. Don't just limit yourself to one kind of plant. This way, you can propagate your entire garden at once!

There are a number of automatic propagator, or cloning machines, available for you to root cuttings. This is an aeroponic propagator, which sprays a mist of water continuously onto the bottoms of cuttings until they form roots.

Gardening Under Lights Book

A crucial temperature measurement for your plants is the difference between day and night. This change is called the thermoperiod. Plants rest at night in cooler temperatures, when photosynthesis, respiration, and transpiration slow, and recover from stress and water loss. Cooler night temperatures can also increase flower size, keep flower color vivid, and extend flower life.

If you’re growing plants in a tighter enclosed space, such as a small closet or a sealed grow tent, pay close attention to the heat output of your lamp. Many grow tents specify that, for example, you need to air-cool the tent when using a lamp that pulls more than 600 watts. Otherwise far too much heat will build up inside your tent.

Gardening Under Lights Book