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This is a comprehensive and newbie friendly guide to cactus and succulents growing. Growing cactus and succulents (CnS) in the Philippines can be challenging. CnS originate in areas where it is hot and arid while the Philippine environment is generally hot and humid. Humidity is the opposite of aridity! Without proper care CnS can easily die in tropical conditions.

Contents

• What are Cactus and Succulents
  • Succulents Store Water
  • Succulents Use Crassulacean Acid Metabolism
  • Succulents Have Shallow But Expansive Root Systems
• Proper Care
  • Pot
  • Potting Mix
  • Proper Watering Steps
• Proper Care Tips
  • Use a Test Pot
  • Don’t Use Sprays
  • Don’t Use Top Dressing
  • Don’t Use Terrariums
  • Drainage Holes at the Bottom of the Pot
  • Use Terracotta Pots
  • Use a Dry Box
  • Water in the Morning
  • Give Them as Much Sunlight as You Can
  • Fertilize in Moderation or Not at All
  • Put Succulents Inside an Air Conditioned Room at Night
• Common Misconceptions
  • Succulents Photosynthesise at Night
  • Succulents Grow Indoors
  • Succulents Can Grow on Rocks
• Additional Questions
  • Can I use SNAP on Succulents?
  • What is humidity?

What are Cactus and Succulents?

All cactuses (“cactuses” and “cacti” are both correct plurals of “cactus”) are succulents but not all succulents are cactus. In this post I’ll refer to both as succulents.
Succulents are plants with fat leaves and/or stems that are used to store water. Succulents have adapted to arid environments.

In their natural habitat succulents receive very little water. Rains are few and are far between and the landscape experiences dry spells. In their natural environment it is arid. The air contains very little moisture (low humidity) which means water, if available evaporates quickly. When it rains in the desert it floods. The floods carries with it rich nutrients from the desert landscape thus enriching the soil. Remember the rain is not nutrient rich. Only when it hits the ground or collect as floodwater does it get infused with nutrients which in turn gets distributed through out the landscape. Because it is arid the water evaporates quickly.

These are the conditions that succulents has adapted to. To survive succulents generally have the following adaptations: water storage through succulency and crassulacean acid metabolism.

Succulents Store Water

Storing water is one of the ways plants survive in arid environments. Succulents store water in their leaves and stems in the form of juice or sap. Succulent is derived from the latin word sucus which means juice or sap.

Succulents Use Crassulacean Acid Metabolism

Plants transport water and nutrients in a process called evapotranspiration. Plants draw water and nutrients through the roots. Water move through the plant via the stem. Water then escapes as water vapor through the stomata. Up to 98% of the water taken up by plants escapes as water vapor through this process. This is something that succulents cannot afford in the dry environments where they originate. To combat this they developed the crassulacean acid metabolism or CAM. With CAM the succulent keeps their stomata closed during the day thus preventing water from escaping. To photosynthesise they used carbon dioxide they stored  previously.  Then at night their stomata opens allowing for the exchange of gases which will allow the succulent to store carbon dioxide in a form of an acid.

Succulents Have Shallow But Expansive Root Systems

As mentioned earlier water is a premium in the environments where succulents originate. When water does come they must make the most out of it to be able to absorb as much water and nutrients as they can before it all evaporates.

During dry spells succulents put out roots to try and find water and make sure they are going to make the best out of the next rain. When rain does come their roots are ready to make the most out of it. They will suck up all the water they can as fast as possible and store them in their leaves and stems. The soil will soon be dry again and they will grow more roots and so on.

That is why it is very important that succulents receives dry spells. It is during dry spells that much of the root growth happens. The more root they have the better they can absorb water and nutrients when rain does come.

Proper Care

We now know basic but important information about succulents. To grow succulents successfully we must do our best to replicate the growing conditions for our potted plants. The conditions, NOT the landscape. For example, you can’t take a cactus out of the desert; put it in a pot using the rocks, pebbles and silt from the desert; take it with us to the Philippines; put it out in the sun and rain and expect it to grow.

First of all, it rains here too often. Secondly the air is so humid because the country is surrounded by water. The end result, the pot could stay wet for too long. Wetness is bad because it promotes the growth of microorganisms that can cause problems for the plants.

Remember, in their natural environment succulents doesn’t have to deal with wetness for very long. That is why they don’t have that much defense from water borne maladies. If they stay wet in their pot for too long. Sooner or later rot will result.

That is why it is important that your potting mix is fast draining, quick drying and airy.

Pot

Terracotta pots are the best. Terracotta pots are porous. They allow moisture to escape and thus allow your potting mix to dry faster. Terracotta pots can be cumbersome however.

Your pot should be big enough to allow the root ball to occupy 1/2 to 2/3 of the volume of the pot. When in doubt err in the side of caution and under pot. Larger pots collect more moisture and takes longer to dry.

Be sure that your pot as drain holes at the bottom. Drain holes are required because otherwise water pool inside your pot and kill your plant. It should also be at the bottom instead of the side. Side drain holes still allows a small amount of water to pool at the bottom which will supply moisture through out the entire pot.

Potting Mix

There are as many succulent potting mixes as there are succulent growers. The amount and type of materials you use should apply to your environment.

Fast Draining

The mix must not retain water. Again it is important that our growing medium dries as quickly as possible. One way to check if your mix is water retentive is by comparing its dry and wet weight. If your mix become significantly heavier when wet, then it is water retentive.

Quick Drying

The longer the pot is wet the longer the plant has to deal with the problem instead of doing other things like growing  or reproducing  (flowers/fruits/seeds). Your potting mix should be allowed to dry quickly. One way of allowing your pot to dry faster is by not using top dressing. Top dressing can prevent water vapor from escaping the pot and slow the drying process.

Airy

Plants need to breathe too. Roots need oxygen from the air. In addition, air circulations culls the growth of anaerobic bacteria (bad ones). Air circulation speeds up evaporation too. One of the signs of a good mix is when it makes a faint sound when you pour water over your pot. Those faint gurgling sound is a sign that fresh air is being pulled inside your pot aerating the roots and keeping them healthy.

Proper Watering Steps

Proper watering, again, is based on the conditions in their natural environment. In their natural environment, there are periods of dry spells. Rains (and other forms of precipitation) drenches the soil. Then it all drys up again. To water properly follow these steps:

1. Wait until the medium is thoroughly dry.
2. Add water until the pot is thoroughly wet.
3. Repeat.

Make sure the pot is dry. You’ll be surprised how, even an excellent medium like pumice take so long to thoroughly dry because of how humid the environment is.

Do not follow a schedule. “Water once a week.”, is a common advice but this can be harmful for your succulent. It can take more than a week for the potting mix to dry and if it remains wet for too long  death will occur.

Proper Care Tips

Use a Test Pot

Take a pot similar to those used by your potted succulents. Fill it with the same potting media you use with your succulents. This is your test pot. To use simply water your test pot until the medium is thoroughly wet. Take a BBQ stick and stick it into the center of the potting medium. Push it down to the bottom of the pot. Wait for a couple of minutes. Pull it out and feel the stick for moisture. If there is moisture the pot is still wet. You’ll be surprised how long potted media take to thoroughly dry.

You can use it to tell if you should consider watering your collection. Water your test pot along with the rest of your succulents following proper watering steps. You can use the test pot to tell you when to water. Check you test pot for moisture to tell if it is OK to water your succulents.

Don’t Use Sprays

Spraying succulents will do no good because most of them have a waxy covering to keep moisture in and this also keeps the moisture out.

Spraying the growing medium will do more harm than good. Spraying the top of the growing medium can result in bad root development. Remember that the medium should be thoroughly wet if one follows the proper watering steps.

Don’t Use Top Dressing

Don’t use them. Unless, you are following proper watering steps or made adjustments elsewhere. Top dressing can trick you into believing your pot is dry. Top dressing also hinders evaporation. Even if your medium is porous and airy often times top dressing is not. The top dressing prevents water from escaping and can keep your medium wet for longer.

Don’t Use Terrariums

Don’t use them. Unless you’re quite experienced in succulent care. Terrariums act like a humidity dome that traps moisture in. This is one of the worst place for succulents to grow.

Drainage Holes at the Bottom of the Pot

This is very important. Without this your plant will sit in water and drown (roots need oxygen from the air) or rot.

Drainage holes to the side is OK as long as you make sure that water doesn’t pool at the bottom of the pot.

Use Terracotta Pots

They can be cumbersome but are the best option. They are porous and it wicks away moisture from your medium and exposes it to the outside of the pot thus increasing the rate of evaporation. If you are in hurry to dry them up you can use a fan to speed this up further. Air movement increases the rate of evaporation.

Use a Dry Box

It is just a box with a dehumidifier inside. You can buy dehumidifiers from hardware stores. The more you put in your box the more arid the conditions will be inside the box. That is because dehumidifiers removes the humidity from the air thus the name. This increases the rate of evaporation of your pot. It is best to do this overnight so that you don’t deprive your plant of sunlight.

Water in the Morning

Following proper watering steps. If you water in the morning your pot and succulent will be exposed for up to 12 hours of warm temperature and sunlight. Water evaporates faster when it is warm. In addition, succulents (and other plants) generally do a lot of work at night. Topping them up with watering the morning makes sure they are ready for the day ahead.

Give Them as Much Sunlight as You Can

Succulents (generally) are not indoor plants as many would lead you to believe. They live outdoors in the middle of the punishing desert heat. They are not used to receiving very little sunlight. If they do not receive as much sunlight as they need they will etiolate in an effort to find more. They stretch, become less compact, and their stems become weak. Etiolation is not a normal thing. It happens because they are desperate for sunlight. Etiolation means they are not healthy and this makes them even more vulnerable to rot caused by overwatering.

Fertilize in Moderation or Not at All

In the desert, succulents generally survive in poor soil and nutrients are only brought in by the occasional flooding. To adapt to this environment most cacti grows slow. If they grow slow they won’t need that much nutrients. Pumping your pot with fertilizers could be harmful. Always start at half dose and increase gradually until your reach the recommended dose or a sweet spot you are happy with. In most cases you can forgo adding fertilizers because succulents are used to growing in areas with very little nutrients in the soil.

Put Succulents Inside an Air Conditioned Room at Night

Desert nights are cold. Air conditioning also lowers the room’s humidity which can aid in drying up your pots. If you spend your night sleeping in an air conditioned room, consider taking your succulents with you. Cold nights are perfect for your succulents and can give them their trademark stress coloring. In addition, colder nights trigger flower production in some succulent species.

Common Misconceptions

Succulents Photosynthesise at Night

No they don’t. Photosynthesis require light, so like other plants they do photosynthesis during the day.

Succulents Grow Indoors

No, most succulents cannot survive indoors. Succulents require lots of light in order to survive. Growing them indoors will result in etiolation and very likely death.

Succulents Can Grow on Rocks

No, they can’t. Succulents can survive in environments with very little nutrients but like most plants they can’t survive without them. Only the Mexican giant cardon (Pachycereus pringlei) and a few others have developed to ability to extract nutrients from rocks.

Additional Questions

What is humidity?

Humidity is the amount of water vapor in the air. Humidity dictates how fast water evaporates. The higher the humidity the longer it takes for water to evaporate. The Philippines is surrounded by water which makes the air very humid which means wet stuff tends to stay wet for longer.

Can I use SNAP on Succulents?

Definitely. If you’re using a totally inert media like pure pumice or scoria you can use diluted SNAP working solution to supply their nutrient needs. The left over nutrient solution you collect after harvest works well.