Tag: science experiment

Weekend Science Fun: Plant Propagation

Want to get more greenery without spending the other kind of green (money)? Let’s take a look at how plants make more plants in ways other than from seeds.

A number of plants can be grown from parts of donor plants by taking what are called cuttings. The cutting is simply a stem with some leaves attached that has been cut off the donor plant. The cutting is then placed in water or moist soil, and over time roots develop.  Once the roots develop, plants in water can be moved to soil and in no time your new plant will be growing and sending out new leaves.

Examples:

Philodendron, geranium and coleus – cuttings can be started in water.

pothos

pothos

Pothos Ivy – cuttings can be placed in water, then moved to soil after roots develop.

jade

Jade plant  – cutting start in water or soil.

cactus pad

Prickly pear – can be started by simply placing pads in the soil.

saguaro seedling

By the way, cacti can also start from seeds. This is a saguaro seedling.

spider plant

Spider plant  – take the offshoots or baby plants and place in soil.

aloe with pups

Aloe and agave- the main plants send off small plants from the roots, called pups. The pups can be separated and replanted. The pups of the above aloe are slightly reddish in color and are towards the lower right in the pot.

Potential science experiments/activities:

1.    Learn the plant parts for different species of plants. For example, is the pad of a cactus a leaf or stem? What is a node? What is a petiole?
2.    Can you start a plant from the cutting of just a leaf, or does the leaf need to be attached to a stem?
3.    Treat some cuttings with commercial root starting hormone and compare to cuttings from the same plant without hormone. How do they differ over time? Figure out how many plants grow from each treatment, what their value is, and how much the hormone cost. Is it cost effective?

Edit: We got some hormone rooting powder this weekend and were surprised to find out that it is quite hazardous. You might want to read the label before you buy it. Be sure to read and follow all the instructions.

4.    Do jade plant cuttings start better in water or moist soil? What about in moist sand or cactus mix?
5.    Under what conditions do spider plants send out offshoots? How old do they need to be to start making more spider plants? How big? Do they make more when they are healthy or when they are stressed? How would you test these questions?
6.    Do spider plants ever flower? What about pothos ivy, aloes or agaves? If they don’t flower, can they make seeds?

7. Do aloes/agaves make more pups when they are in small pots, large pots, or when they are planted in the ground? This would be a long term study.

Hope you enjoy growing new plants. Let us know how your experiments turn out, or if you have any more suggestions for experiments or activities.

Note:  Most of the plants noted above can contain irritants or toxins, so keep them out of reach of small children.

Fat Monday

I have two ideas for today and they both have to do with fat.

First, did anyone read the Weekend Fun for making cheese? One of the cautions was to watch out because the milk can suddenly bubble up and over the pan when heating. I have had that experience a couple of times. I began to wonder why milk would act this way whereas water does not.

The answer goes back to the fact that oil and fat float on water. While heating, the milk fat forms a layer at the surface, repressing the activity of the liquid underneath. At boiling temperatures the fat layer splits all of a sudden, allowing the liquid underneath to roil up violently. Soymilk, with added oils, can have the same reaction.

How would you test this idea? I would suggest seeing whether heating nonfat milk had the same reaction. Then add oil to nonfat milk and do the test again. What happens? Do you have any other ideas?

The next part has to do with another kind of fat. Take a look at this article on how the species of bacteria in your gut during early childhood may determine whether you are obese later on.

I knew a little about how important gut microorganisms are in other creatures. My favorite critters, the insects, have many bacteria and/or protozoa inside them performing all sorts of roles. For example, termites can’t really digest the wood they eat. They carry tiny organisms inside that are able to digest wood. Without them, the termites would starve.

Obviously we have a lot to learn about our own relationships with microorganisms.

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