Updated at: 21-06-2022 - By: Sienna Lewis

Physical indications, growth rate, and scientific methodologies can all be used to measure plant growth. To assess if you have a greenhouse problem, you need to know how to measure plant growth. There must be an issue with the environment if your plants aren’t growing at a reasonable pace.

What would you use as a yardstick to measure plant growth by? When a plant’s size increases in an irreversible manner, you might say that it is growing. Development of leaves, flowers or fruits is also included in this process.

Consequently, as a greenhouse gardener, you must be familiar with foolproof methods for determining the growth of your plants.

Ways To Measure Plant Growth: Easy Fool-Proof Guide

Physical signs

When it comes to monitoring greenhouse plant growth, the most easy method is to watch for physical changes in the plants. Professional gardeners frequently recommend that while beginning seeds in the greenhouse, the quality of the seeds be checked to ensure germination. A link between seed size and plant growth has been shown in studies.

Effect of Light on Plant Growth

Since large seeds can better support themselves at the beginning, you should expect larger plants. Even though little seeds have a better survival rate, they can nevertheless grow plants of the same size. As your plants mature, use this information to anticipate physical changes.

If you want to see a difference, you can take a measurement of the plant every three days and compare it to the previous measurement. There are even gardeners who will take measurements of the leaves to see how many have grown and what their average breadth and length are. Measure the surface area of each leaf by using grid paper.

Growth rate

When it comes to measuring the growth of plants, one of the most frequent methods is to use the growth rate formula. You may calculate the average daily growth rate using a method that subtracts the second measurement from the first and divides the result by the number of days between the two measurements. As a general rule, this is a good way to measure the growth of the leaf.

The growth rate of fresh and dried plants can also be calculated. Begin by weighing a plant for a month, and then repeat the process. After then, you can utilize the aforementioned formula.

Alternatively, drying the plant in an oven before weighing it is an acceptable alternative. After two weeks, repeat the weighing and record the results. To determine the rate of increase, use the same formula.

Scientific approaches

If you prefer a more scientific approach, you can measure the plant’s root growth. However, this procedure should only be used as a last resort because it removes the plant from the soil. With roots, you can use the grid intersect and root shoot ratio to measure growth.

In the first case, the roots are laid out on a grid paper and their intersections are counted. You’ll also need to gauge the diameter, count the number of roots, and determine the length of the roots. Root diameter measurements are particularly relevant for crops with conspicuous roots, such as carrots and beets.

A drying oven and a cutting from the top are required if you prefer utilizing the root shoot ratio to measure. Get the dry weight of the roots and shoots by weighing each portion individually. It is also an excellent predictor of the health of your plants if you compare it to a control group’s root shoot ratios.

What Makes Plants Grow

Learn more about how plants develop if you’re not happy with your findings. It is easier to manage parameters like temperature and lighting in a greenhouse. These places make sure that the indoor conditions are just right for your plants to thrive.

In addition, you need to know how the greenhouse facilitates photosynthesis. In the end, this is how plants get the nutrition they need to keep growing and flourishing. Find out if the greenhouse is able to supply all of the limiting variables, like as CO2, water, and light intensity.

Learn how to properly maintain the greenhouse in order to avoid problems like weeds, fungi, and pests. Even if you’re a newbie, greenhouse gardening is a worthwhile venture even if you’ve never grown a plant before.

Weighing Plants: Fresh vs. Dry Weight

  1. Get rid of any loose dirt by removing plants from the ground.
  2. To get rid of any extra moisture on the plants, gently dab them with a soft paper towel.
  3. Weigh yourself as soon as possible (plants have a high composition of water, so waiting to weigh them may lead to some drying and therefore produce inaccurate data).
  4. After removing the plants from the dirt, make sure to thoroughly clean them to remove any remaining soil.
  5. Blot the plants to get rid of any extra moisture on their surface.
  6. Overnight, dry the plants in a low-heat oven (100°F).
  7. The plant tissue will absorb water when left to cool in a humid setting (such as a Ziploc bag). Weigh the plants once they have cooled down.
  8. Water makes up the majority of a plant’s weight, so you’ll need a scale that measures in milligrams if you want to weigh a dry plant accurately.

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Root Mass

Root mass is advised as a final measurement because it is necessary to remove the plant from its growing medium in order to obtain precise measurements. Root mass can be measured in a variety of ways, depending on the root type and structure.

  • Remove it from the ground.
  • Acidic staining may be necessary if you are working with light or thin roots.
  • Make a grid with the roots and count how many times each root intersects it.
  • Make paper tracings of the roots, measure them, and use the measurements to compute the root length.
  • The number of roots can be counted.
  • Take a measurement of the root’s circumference. Root vegetables with large roots, such as beets, carrots, and potatoes, benefit greatly from this technique.

Root Shoot Ratio

Having a healthy root system is essential to a plant’s ability to take up water and nutrients from the surrounding soil. If you want to get a sense of how healthy your plants are, you can use the root:shoot ratio. For each of your plant varieties, you’ll have a “normal” root:shoot ratio in your control group; any deviations from this normal level (up or down) indicate that your plants’ health has deteriorated. An accurate picture of your plants can only be gained by combining data from the root:shoot ratio with data from observations. Root-to-shoot ratio can be an indicator of a healthy plant if it rises as a result of an increased root size and not a drop in shoot weight. The root:shoot ratio can be calculated as follows:

  1. Removing the plants and rinsing the soil of loose particles is the first step.
  2. 2Blot the plants to remove any unabsorbed moisture from their surfaces.
  3. Overnight, dry the plants in a low-heat oven (100°F).
  4. A Ziploc bag can be used to keep moisture out of the plant’s environment while it cools down, however in a humid atmosphere the tissue will absorb water. Weigh the plants once they have cooled down.
  5. Remove the top layer from the root (cut at soil line).
  6. Each plant’s root and top should be weighed and recorded separately. Root/shoot ratio (dry weight for roots/dry weight for the top of the plant)
  7. Each treatment’s root/shoot ratio can be figured out in before.
  8. Water makes up the majority of a plant’s weight, so you’ll need a scale that measures in milligrams if you want to weigh a dry plant accurately.


Various characteristics of a plant can be observed and used to gauge the growth and health of that particular plant. Some of the measurements you can take and the frequency at which you should make these observations are listed in the following table.

  • From the container’s edge to the top of the main plant stem, measure the height of the main plant.
  • As a reminder, you should not measure from the top of the soil because the earth will condense over time as a result of irrigation.
  • The number of leaves on each plant should be counted and recorded.
  • Including the tips of newly emerging leaves, make a complete inventory of the plant’s leaves.
  • To avoid counting mistakes, you may want to set the plant on graph paper.
  • To get a rough estimate of the surface area of each leaf, trace the leaves on graph paper and count the squares covered. Make sure you do this for every leaf on every plant in your experiment.
  • Method 2: Make a paper tracing of each leaf. The paper should not be damp, and the type of paper should be consistent. Weigh the leaf tracings you made by cutting them out. Calculate the average leaf area for each plant by weighing the cutouts and dividing the total weight by the number of leaves. Each plant in your experiment should be subjected to the same procedure.
  • Using a digital camera, take a picture of a plant and analyze it. Look at how many leaves there are by measuring their surface area with specialized software.

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In the greenhouse, growing plants from seedlings is an immensely fulfilling experience, especially when you watch them flourishing. Because of this, it’s essential to know the best methods for measuring plant development. Calculate growth rate, grid intersect technique, and root shoot ratio among other physical indicators to help you in this endeavor.

Although they may appear daunting at first, these are actually rather simple to follow. It’s important, however, to know how to do it the right way for your particular plant. Since you’re removing the plant from its growing medium, your best bet is to use methods that don’t require the plant to be submerged in water.

In general, it shouldn’t be difficult to gauge plant development. Check to see if your plants are developing at a suitable pace. Make adjustments in the greenhouse if you aren’t satisfied with the results of your plants.