Before adding a soil amendment to a houseplant, check drainage, moisture, root space and light. A droopy leaf is a reason to investigate. It does not tell you which bag to buy.

Give your plant a quick check before changing its growing mix. These four observations help you choose the next step with more confidence, whether that means adjusting watering, planning a repot or choosing an amendment.

1. Give water a way out

Start underneath the pot. Does the growing container have an open drainage hole? If it sits inside a decorative outer pot, check that water has not collected around it.

When you water, let the excess drain away and empty the saucer or outer pot. University of Maryland Extension recommends letting water drain freely and discarding what collects below. A plant should not be left standing in that water.

Skip the gravel layer at the bottom. Maryland's repotting guidance advises against filling the base with gravel. Start with a suitable container and growing mix instead.

2. Check the mix before following the calendar

A weekly reminder is useful for checking plants, but it should not automatically mean watering every one of them.

Feel the growing mix below the surface and notice the pot's weight. Compare it with how the same pot feels after watering and draining. Check your plant's moisture needs, too: a cactus and a peace lily should not share one watering rule.

Maryland explains that both too little and too much water can cause wilting. Look at moisture before treating a drooping leaf as a request for more water or more nutrients.

3. Look for a reason to repot

Roots circling tightly inside the pot, roots emerging through drainage holes or unusually fast drying are reasons to assess whether a plant needs more space. University of Minnesota Extension recommends repotting only when needed and choosing a pot just one size larger.

A much bigger pot is not automatically an upgrade. Extra growing mix can hold more water than the plant needs. Spring is generally the best time for routine repotting; a healthy plant does not need its roots disturbed just because the season changed.

4. Check light and what is already in the mix

Notice how much light reaches the plant now, rather than relying on where it did well last summer. University of Georgia Extension explains that fertilizer demand falls when winter light and growth decrease. Slower growth is not, by itself, proof that you need to add more.

Read your potting-mix label before adding another input. Some mixes already include fertilizer. University of New Hampshire Extension recommends checking ingredients and choosing a mix suited to the plant; orchids, succulents and cacti can need a different base from other container plants.

Choose the purchase that fits the job

If you are filling a new indoor pot, begin with a growing medium intended for that plant and container. If your current setup stays wet, address the container, watering and mix before adding another material. If your plan calls for a vermicompost amendment, compare the product's ingredients and directions with that plan.

For help telling the categories apart, read compost, topsoil or potting mix and worm castings and vermicompost: what's in the bag?

Where Soily fits

Soily Premium Worm Castings Blend + Biochar is a soil amendment to use with your growing mix. It is a vermicompost blend with biochar, rather than pure castings or a complete potting mix.

Choose from 2.5, 5 and 10 lb bags. The 2.5 lb bag is the smallest purchase; all three sizes contain the same blend. Bag weight does not tell you how many plants it will cover without a suitable application plan.

Have the right growing mix and a plan for an amendment? Compare Soily bag sizes and see the current offer. You can also explore how we make the blend before choosing.