Updated: Apr 27, 2020
The first three points I make here are very easy to understand. The last two are plant science concepts that I think everyone should learn! I love plant science and hope that you all can take something away from this article.
People always put plants by windows to get more light, but you should always make sure it isn't too cold at night by the window. Try to use south facing windows if you are in the northern hemisphere and north facing windows if you are in the southern hemisphere for plants that need more light. The best way to keep plants happier in the off season and get some beautiful flowers is to use supplemental lighting. It can be low wattage and still make a positive impact on your plants. I use T5 fluorescent fixtures that come in all 2 and 4 foot versions with 1, 2, 4, 6, or 8 bulbs. I buy mine at HTG Supply. I also love using LEDs indoors, you just have to get right ones that have a good quality light.
I always judge whether or not I should water by the weight of the plant. I never judge it by just putting my fingers in the soil because a lot of times, the top of the soil is dry and the rest of the pot may be wet still. The root ball on a plant in soil dries from the outside in so if you pick up the plant and see how heavy it is you can better judge if it needs water, or if it is still wet at the core. The more you pick up the plant, the easier you will be able to tell if it needs water. Also note that every type of plant is going to be different and even plants of the same type may need water at different times.
Always be scouting for bugs that may be harmful for your plant. If you aren't looking, you'll never find any! Common pests on indoor plants include spider mites, aphids, thrips, fungus gnats, and sometimes scales. I always look for yellowing leaves and flip them over, that is where mites and aphids like to hang out. Hang yellow sticky cards around to catch pests and identify them before they get out of hand. Use essential oil blends (they make them specifically for plants, you can find them at the local grow store or online) to preventatively spray for pests. I'll be posting more about pest management programs in the future!
4) Transpiration (Let's get scientific)
One of the most important concepts of plant science is transpiration, and understanding it can help you understand why your plant grows faster or slower at certain times. In most regular plants, water is taken in through the roots, and this is common knowledge. After that, the water goes up the stems and into the leaves, and out these really tiny holes called stomata using negative pressure. So, depending on the pressure and humidity in the room the plants will uptake water and nutrients at different speeds by opening or closing their stomata. They also use the stomata to take in CO2 which they need to do photosynthesis. So in a room with positive pressure, your plants will uptake water slower and grow slower in general. In a room with slightly negative pressure your plants will uptake water a bit faster.
It is good to realize that there are a lot of small environmental factors that influence the growth of your plant, and always remember that it may not just be your actions that are hindering a plant from growing or flowering. It may be that the environment isn't favorable for the growth of the plant, which leads me to my next tip.
5) Vapor Pressure Deficit-------->FIND THE CHART HERE
Understanding VPD! It is basically the concept that the relationship between humidity and temperature effect the growth of the plant. Click the link above to see the chart!
For example, if there is low humidity and a high temperature, the plant has to draw more water up through its roots and out the leaves. It has less optimum growth in these conditions and has to work harder to survive. If the humidity is too high while the temperature is too low, the air becomes saturated with water and water will cover the plant leaf like dew. This causes the plant to draw less water in and stay wet for longer, resulting in possible root rot or other molds. I like to be aware of the number I am in so that I can plan my watering and care accordingly. The higher the number on the chart, the faster the plant uptakes water. I use a little battery powered temp and humidity monitor to track my room's VPD.
An example of a perfect VPD would be 72 degrees F and 65% humidity. However, between 80% and 55% is still a good range to be in. Also, remember that different plants like different VPD numbers depending on where they originate from.
I hope you see my point here. It's not always an action that you do/don't take that can hinder your green thumb. Remember to step back and observe everything that the plant is experiencing, it may surprise you what they can teach you.
Please comment below if you have any questions or opinions!