Author: Roberta (Page 504 of 561)

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.

Bug of the Week: Cactus Flower Visiters

The cacti are blooming this week.

prickly pear flowers

The prickly pears,

prickly pear flowers

are particularly colorful.

agave flowers

The agaves are flowering, too.

cactus flower

I’m not sure what this one is, but it is spectacular. Anyone know?

All these flowers are producing nectar and pollen galore. The insects are busy.

hedgehog cactus flower with bee

cactus flower

Can you find all the arthropods in this picture? I’ve tried to make it big enough for you to see everything, but let me know if it takes too long to load.

Meet a Scientist Monday: Dr. Philip Christensen

Dr. Philip Christensen, professor of planetary geology at Arizona State University, carries a piece of Mars with him. Actually, it is a bit of a meteorite from Mars that was found in Africa, but to him it is still a bit of Mars. You can hear the excitement in his voice when he shares it with children. “The next time you look into the sky and see Mars, remember you held a part of it,” he says.

Dr. Christensen’s interest in Mars started when he was a child. He reports that he talked his mom into letting him stay home from school (when he was in sixth grade) to watch the first images of Mars coming from the Mariner 4 spacecraft on TV.  Later, he went to the Jet Propulsion Laboratory and remembers seeing the Surveyor spacecraft that eventually landed on the moon. Although he remained intensely interested in Mars, he admits it never occurred to him that people actually got jobs studying Mars. It wasn’t until he was a senior college student at UCLA, and working on a project with Mariner 9 images of Mars, did he realize that he could become a scientist and study Mars as a career.

Dr. Christensen and his team at Arizona State University were responsible for developing THEMIS (thermal emission imaging system) cameras that were on Mars Odyssey. He is also Co-investigator on the Mars Exploration Rover missions, and built the TES (Thermal Emission Spectrometer) carried on the Mars Global Surveyor. Part of his research is looking for evidence of water in the minerals and rocks of Mars.

You may wonder, does Dr. Christensen wear a laboratory coat for this work? No, but he does have to wear a special white suit that covers his entire body when he builds his cameras to prevent contaminating the sensitive equipment.

Hearing Dr. Christensen speak recently, he definitely wants children to know what it took him so long to discover, that anyone can become a scientist. He also wants them to know that science is fun. “We build things and send them to Mars. It’s a fun job.”

Because of Dr. Christensen’s commitment to outreach for children, he has been active in a number of educational programs. Here are links to a few.

The Mars Student Imaging Project allows teams of students from fifth grade and up to participate in authentic Mars imaging research.

Passport to Knowledge has a number of awesome Hands-On Activities, including egg drop projects to simulate Mars landings, rocket science 101, and activities to build your own Mars Rovers from junk.

Rock Around the World allows children to send a rock to ASU to be analyzed (as described in a recent post in this blog).

If you would like to see pictures of Dr. Christensen and learn more, the Phil Christensen Biography is a good starting place.

« Older posts Newer posts »