Question
QUESTION: Hi Darlene,

I'm from Indonesia, temperature 30篊 (day) and 27篊 (night). Have Kalanchoe Blossfeldiana in 3 colours: white, orange, and yellow.

Put them in partial light condition under house roof, use 10" clay pot with some holes, soil mix 75% volcano sand (little bit bigger aggregate than normal sand) and 25% pot soil. Choose this soil mix amid high humidity here. Watering once a week using destilized water, very little amount (approx. 5-6 table spoon).

Have to repot asap after buying with aboved soil mix because here the nursery doesn't provide the right mix (insufficient porous material), around 90% peat and rest pot soil which caused soggy soil in the past.

Have the following problems:

- Calandiva White: young flower dead/unhealthy prior to blooming. What's the cause and how to solve or avoid in the future ?
This white one was not so healthy when I bought it, but no choice because I couldn't find white multiple elsewhere.

- Calandiva Yellow: found some spider mite.

How much liquid soap is allowed to add in one liter water to kill the insects without damaging the plants especially leaves ? 1 Tablespoon ? 1 Teaspoon ?

Should I add alcohol or vegetable oil in soap water ? How much ?

- Leaves turn yellow and curling. Besides too less or too much water, is it possible that it's because I repoted 2-3 times in one week ? I did it to check the soil moist inside the pot whether or not I have the right mixture and watering. Will not do it again in the future after knowing the right mixture and watering volume.

- What fertilizer should be used ? NPK 2:1:2 or 1:3:1 ? Can I add CaO (Calcium Oxyde) and/or Mg(OH)2 in that fertilizer ? How much ?

I sent some pictures of my Kalanchoe to your email address [email protected].  

Sorry, if too many questions because I tried my best to care those lovely Kalanchoes but always end up in disappointed result (dead plants).
Thank's a lot for your help.

Rgds,

Ari



ANSWER: Ari,

Your Kalanchoe need more sun and more water. When you water you need to give them enough water so all of the soil in the pots are moist and an hour later empty the drain trays. Then do not water again until the plants feel dry and light weight. The easiest way to telll if the plant is dry is by the weight of the pot. Put some dry potting soil in the same size and type of pot, then pic it up, when the plant gets nearly that light you will now it is very dry. Then water it thoroughly and feel the difference. They are succulent desert type plants (but they are from the edge of the desert where they get a little more water than a cactus) that like as much sun as possible. It would be very happy outside in full sun for the summer months. As for fertilizer 1:3:1 would be fine or any fertilisr that says it is for blooming plants. You can add CaO (Calcium Oxyde) and/or Mg(OH)2 at half the strength reccommended on the bottle you purchase it in. I hope this helps. I love kalanchoes too. They are beautiful plants. Good luck.

Darlene

---------- FOLLOW-UP ----------

QUESTION: Dear Darlene,

thank's for the tips, especially regarding pot weight.

However, you haven't answered the soap water mixture effective enough to kill insects such as spider mites or mealybugs without damaging the plants. What do you use/suggest ? Thank's again.

Btw, we can not put Kalanchoes directly in full sun here, too warm and the leaves get sun burn.

Rgds,

Ari

Answer
Ari,

Then put them where they would get dappled sun so they get some sun during the day, or where they will get sun in the morning and evening but not midday. They really like being outdoors with a night time temperature drop.

I actually prefer using 70% rubbing alcohol either straight in a spray bottle or mixed with water at 3 parts alcohol to 1 part water. It will kill insects on contact but does not have residual effect. But as a second choice 1 tablespoon of liquid soap per 1 liter of water will also work but again it doe not have a residual effect unless you add Neem oil to it then it will repell insects for a longer period of time. Neem oil is an effective insecticide/ fungicide that is safe to use indoors and if you mix it with a soap spray it has a longer lasting effect. If insects are a common problem in your area you may have to inspect your plants weekly and spray regularly. Good luck.

Darlene