Raising and Breeding Silkworms

Over the years I have lost quite a bit of money due to failure with silkworms, that's a big reason I made this site is so that you won't make the same mistakes. Silkworm chow can get really expensive when ordering elsewhere in small quantities so be sure you order from us if you need a half pound or a hundred!

What do silkworms eat?

Mulberry leaves — and essentially nothing else. Silkworms are one of the pickiest eaters in the insect world: after thousands of years of domestication they're hardwired to the mulberry tree (Morus alba and its relatives), and a silkworm that hatches onto anything else will usually starve rather than switch. You'll find claims online that they'll take lettuce, carrot, or beetroot leaves in a pinch — technically some will nibble for a day or two, but they won't grow properly on it and most die before spinning. Treat "mulberry or mulberry-based chow" as the whole menu.

Fresh mulberry leaves

If you have access to a mulberry tree (any fruiting or fruitless white mulberry works), fresh leaves are free food. Pick young, tender leaves for small worms and tougher mature leaves for the big ones, rinse and dry them completely — wet leaves cause the gut problems that wipe out trays — and feed once or twice a day. The catch is seasonality: leaves disappear in fall and winter, and worms fed on leaves will often refuse chow later, so pick one lane before you start a batch.

Silkworm chow (what we raise ours on)

Silkworm chow is dried, powdered mulberry leaf blended so it cooks into a firm gel. It's how we raise millions of silkworms year-round: consistent, available in January, and free of the pesticide risk that comes with leaves from a tree you don't control. Mix our powdered silkworm chow with water, microwave or steam it, let it set, and grate a thin layer over the worms — they crawl up onto fresh food and leave old food and frass behind. A half pound of dry powder makes roughly 1.5 lbs of prepared food, enough to take a small batch from egg to cocoon.

What not to feed

• Wet or wilted leaves — moisture on the food is the #1 killer of young silkworms.
• Leaves from sprayed trees — silkworms are extremely pesticide-sensitive; one treated leaf can end a tray.
• Other plants — osage orange is the only semi-workable emergency substitute, and it's a last resort, not a plan.

Deciding between hatching your own and buying ready-to-feed? Live silkworms ship at feeding size, or start from eggs with a bag of chow and raise them exactly the size your reptiles need.

Hatching Eggs

You will find many sites saying you must do this in order for the eggs to hatch. Some say you must have an incubator, it's not necessary (but I would recommend it even if you build your own). When I first started I did not have an incubator, but I had a room that I always kept in the 80's which is ideal for silkworms. One of the most important parts, in my opinion, in the very beginning is overcrowding. Every site that I can remember has said to use Petri dishes to hatch eggs, DON'T! they cost way more than necessary! What I do is go to the dollar store and buy some cheap Tupperware (be sure to clean them very well before use, 10% bleach water works great). After you have them cleaned put about 200-300 eggs per small Tupperware container (less eggs = higher survival rates). Get them as close to 80-84 as you can and they should hatch in about a week. (Need eggs? We ship silkworm eggs year-round.)

The First Feeding

The first feeding can be nerve racking, if you grate chow on top of them and it lands on a few it will kill them, if you put chunks in there it will do the same. This is why I came up with my own method of feeding the new born silkworms. I’ll tell you how I came up with the idea (no, it shouldn’t be too long). When I first got my Tegu he wasn’t eating properly so I had to use a syringe to force yogurt into his mouth. At this time I had 5,000 silkworm eggs about to hatch and I thought instead of losing a lot of them with less controlled feeding methods I could put the food in the syringe and make a very controlled line of food where ever I want it to be! This was the most effective feeding method I had ever seen, I would be surprised if I lost a single worm! At the time I was using a tiny syringe that would take forever to refill. I did some searching and found some large syringes on amazon and they make feeding the small worms super easy! When the eggs hatch you put a string of food next to them NOT on them! They will crawl over to it to eat. The next feeding you can put it where they were the first time and they will go back! It makes it so mold doesn’t form because you are giving the food plenty of time to dry by not putting more
food on top of the old.

Past the critical stage

Getting past the critical stage is huge, they are no longer as fragile as the babies are. The critical stage is the first 7-10 days after hatching. At this point it is now safe to transfer them to another clean container. If you think mold may have started to grow and your worms are not past the critical stage you can still transfer them, but be very careful and wash your hands extremely well before handling the baby worms. They should all be fine after the transfer. Once they have reached this stage I no longer use the syringe for feeding, I just put chunks of food around the container, it’s faster and easier. Also at this point you can cut back on feeding if you want to prolong the life of your worms, you will lose a few but for the most part they will last longer.

Large silkworms

When they are approaching full grown size they eat a lot more than you may think! I put a pound of cooked chow into a pile in one of my containers of silkworms to see how long it would last and it was gone the next morning (this was a big container with a couple thousand worms)! Be sure you have enough food to last you through their entire life cycle, buy in bulk - the food can last up to two years!

Spinning cocoons

When they start spinning cocoons they will start eating less, and once they start their cocoon they will never eat again! When you think that your worms are getting close to making their cocoons put toilet paper rolls or even little disposable cups in with them. Give the cocoons a few days to finish before you remove them so you don’t dent the cocoons. Once they are completely done with the cocoon you will be able to shake it and hear them rattling around inside. In a couple of weeks the moths will emerge.

Shop Oregon Silkworms

Ready to start? We raise everything you need right here in Oregon, backed by our Live Arrival Guarantee:

• Silkworm eggs — hatch your own colony from the start.
• Live medium silkworms and live large silkworms — ready-to-feed cups of 25.
• Powdered silkworm chow — the food they need at every life stage.