Yes, cut it off and throw it in the compost heap. It sounds past its prime and on its way to making seed.

If your main head shows signs of beginning to flower, harvest it immediately, taking at least 6 inches from the stem; cut at a slant. Ideally, you should harvest the head before those buds open, because it will be a little tougher and may not be as tasty, but they are still edible, especially if just a few of the flower buds have started to open.

The plant may also, as you have found, produce side shoots that will continue to develop after the main head is harvested. These will not develop into large heads, but are useful to harvest as florets. When they are of a decent size, harvest them to encourage more to develop. Eventually, after several weeks, the plant will stop producing. For more tips on harvesting, check the “Harvest/Storage” section in the above article. Hope this helps!

Hi Floyd, it is best to harvest broccoli when  the buds of the head are firm and tight before the heads flower. 

Sue, the best organic way that we know of to get rid of these pests is to pick them off by hand. Look all over the leaves; pick of the loopers and brush off any eggs. Drown the larvae in soapy water.

Not the most fun project but get out there and show them who’s boss! Good luck!

Do you mean Broccolini, aka baby broccoli? If so, this might help:
http://agsyst.wsu.edu/Broccoli...
Harvest when buds have matured but have not yet opened or developed color. Harvest the main head early to encourage side shoots. Keep a close eye on the buds, as the plant can bolt quickly.

Is this a heading broccoli, broccoli raab, sprouting broccoli, or Chinese broccoli? What country/location are you in?
 
Sometimes too much nitrogen will promote leave growth at the expense of flowering/floret formation. Broccoli, a cool-season crop, also usually requires a period of cold to encourage bud formation; some cultivars are more heat tolerant.
 
On average, broccoli will mature between 60 and 120 days, depending on cultivar and conditions. It sounds like yours has gone beyond that point. However, if you are growing sprouting broccoli, some of those varieties may take as much as 220 days to mature. In this case, wait a little longer.
 
If you are growing regular heading broccoli, you might harvest the tender leaves and start over again, but first, just to be sure, you might ask someone from a local nursery what is normal for your area. If you live in the United States, you can also check your county's Cooperative Extension service:
 
http://www.almanac.com/content...

Hi, Sweet: If your broccoli has not produced anything in 6 months, it is likely not going to, so you should harvest the leaves and get on with something else. Do a soil test to make sure that everything is in balance and that there is not an overabundance of nitrogen. Your fail could also have come from overheating. Good luck!

Broccoli plants can take a long time to form florets and they are a cold weather crop. The plants don't like the heat. Most varieties take 60  to 70 days to grow a head and the plants may be as tall as 3 feet. It's better to leave the leaves on the plant and not cut them off. If by a chance you don't get florets on your plant you can eat the broccoli leaves. Try planting broccoli in late summer for a fall harvest.

Oh, dear.
This could be aphids, or it could be something more serious like sooty mold infection that inhibits photosynthesis (thus, the lime color). Here is more detail: http://cals.arizona.edu/crop/p...
You might find some advice here: http://www.clemson.edu/extensi...
Our advice would be to harvest what might be edible.
And, we would ask, do you rotate your crops? Moving plants around, not growing in the same spot year after year, is one of the easiest/best ways to avoid plant pests and disease.
Best wishes—
 

Depending on the variety you have, and whether you planted by seeds or transplants, it might just be that they aren't ready to form the heads yet. Some take more than 10 or 12 weeks.
 
Another possibility is that the plants are getting too much nitrogen, which encourages leaf growth over flowers (the heads). Depending on the formula of Miracle Gro that you are using, it tends to have higher nitrogen than phosphorus or potassium. Broccoli is a heavy feeder, but it's best to use a balanced organic or slow-release fertilizer if you are applying it every few weeks. Otherwise, too much nitrogen may result in hollow stems and may discourage heading. If you choose a fertilizer high in nitrogen, you might try only applying it about 3 or 4 weeks after transplanting, a smaller amount when the heads are just developing, and then after you harvest the main head (to encourage small side shoots to grow, which you can also harvest). (Before planting, the soil should be amended with composted manure or similar to provide rich nutrients.)
 
Hot temperatures may also prevent heads to develop, or encourage the plant to bolt (form a flower stalk immediately instead of first developing compact heads).

It sounds like your broccoli bolted (developed a flower stalk and went to seed). This happens when temperatures are too warm, or temperatures fluctuate from quite cool for a while to warm. Broccoli likes consistently cool weather (about 65 to 75 degrees F ideal), and in many areas is best planted in early spring or late fall. Bolting can also happen if the plant is under stress, such as diseases or insects, or weeds. To help prevent premature bolting, you can select slow-bolting varieties, plant at a good time for your area (if you live in the U.S., see your local Cooperative Extension for best times: http://www.almanac.com/content...), keep plants watered and stress-free, and keep the soil cool by providing a thick layer of mulch.

We tend to use blood meal (high nitrogen) as a side dressing; blood meal won't substitute good soil that's mixed with lots of organic material. We side dress with one cup for every 10 square feet of growing area. Side dress 4 weeks after transplanting/thinning; Apply another half cup when the broccoli head is the size of a quarter; side dress a third time after the main head is harvested for continued side-shoot development. Place the fertilizer 6 inches to the side of the plant and irrigate it into the soil.

We'll try to help. It's very early spring do we're wondering if you are tranplanting too early but it all depends on where you live. Broccoli is temperature sensitive.  The ideal temperature for broccoli is between 65 and 80 degrees.  If it drops below 40 degrees, you'll have issues. You can check your local planting dates for both starting seeds indoors and setting plants in the ground here:
http://www.almanac.com/gardeni...
 

Mildred, Floating row covers are also called "gardening fabric." You can find examples on garden seed sites such as www.Burpee.com and www.gardeners.com.  When you get to their web sites, just type in "floating row covers." Hope this helps.

Thanks for asking. We've clarified the text on this page. Plant each seed at a depth of 1/2 inch to 1 inch. Within a row, the spacing is 12 to 24 inches apart with 36 inches between each row. If you overseed, you'll just want to thin the seedlings so that they're no closer than 12 inches apart.

Cole crops such as broccoli, especially plants that are not disease resistant, are commonly affected by several problems. It’s not possible to know exactly what has afflicted your plants but here is some information.
• Seeds and young transplants can be affected by the soil-borne fungus Pythium. Control recommendations include planting in raised beds, ensuring good drainage, and planting in commercial potting soil, not “earth," which is to say garden soil.
• Fusarium yellow, which has a yellow-greenish tint, can live in the soil for years without a host plant. When the opportunity presents itself, the disease enters through the plants' roots as well as any injuries caused by insects or transplanting.
By planting disease-resistant varieties and rotating your crops, you can help your plants to avoid these and other diseases and so improve your harvest.
We hope this helps!

Floating rows are simply lightweight fabric covers that you drape over your plants. Here is a good article with pictures on the Burpee seed site: http://www.burpee.com/gardenin...

Broccoli isn't the best veggie for seed-saving but you can do it. First, note that you can't have any other crops from the Brassica oleracea family within a mile or they'll cross-pollinate and it won't be pure broccoli. Also, you want to seed save from heirloom veggies versus hybrids. Do not harvest heads on broccoli plants that you wish to save for seed. Carefully dig the plants and pot them in sand. Store plants between 32-40° F. Plant back out in early spring and allow to bolt. Harvest seed pods when dry and clean by hand. See more on Seed Saving: http://www.almanac.com/content...

Broccoli prefers cool temperatures and an even supply of water to produce heads.Hot temperatures and/or drought can cause broccoli to stop producing heads. Overcrowding and poor soil can also cause problems. Leave the plants in the soil and see if the cooler weather will help the broccoli to set heads.

Broccoli is usually grown as an annual and started new each spring. You can leave your plants in the ground after you pick the main crown and harvest small shoots that grow from the sides of the stems. In late fall remove the plants.
 

Yes, you need to pull the plants. Brocolli, a cool-weather plant, is a popular fall crop in most regions if you wish to try again!

Here is a good reference page on food safety: http://www.foodsafety.gov/blog...

Hi, Pam, Here are tips on how to cut broccoli from our organic gardening blogger, Celeste: http://www.almanac.com/blog/ce...

If the temperature is too warm, the broccoli will not produce heads. Broccoli is a cool-weather crop grown in spring and fall.

Broccoli is a cool season plant. Local (to you!) sources suggest that the best growing time in your area is fall, but some of the sources seem to have conflicting information. Some say start in winter for spring planting. Just as important, though, is the soil. Cole crops like a pH betw 6 .0 and 7.0 (even 7.5); rich, organic compost; plentiful, consistent moisture; and some say a shot of nitrogen at planting (but not too much; that could cause hollow stems). Finally, consider where it is planted in terms of crop rotation: Broccoli and other cole crops should not be planted in the same location more than once every three or four years. Hope this helps—

A layer of 2 to 4 inches of mulch will help cool the soil (about 4 to 6 degrees cooler). However, you need to harvest broccoli before the flowers open or show yellow. The mulch will help slow down the heat but the broccoli will keep maturing!

My broccoli can get quite tall before the head starts to form. Even knee-high. It can take 60 to 70 days for some varieties. If you gently push the little leaves away in the centre, can you see florets forming? It may just take some time. If the heads do not form, it's usually due to extreme temperature--usually because it's too hot. This cool-weather veggies does not like heat. Cold shock at seeding can happen, too.

After you get the true leaves (within a week or so), the cotyledons will start to yellow. When they start to yellow, begin fertilizing seedlings by applying a WEAK fertilizer solution each time you water. (Be careful not to "burn" with too much fertilizer.)

Reasons for long stems: temps too warm (broccoli likes it 10 degrees cooler than most seedlings), not enough direct sunlight, too much nitrogen in soil. Yes, when you plant, cover the roots and stem with supplemental top soil; dissipate the nitrogen (use fertilizer high in phosphorous and low in nitrogen). Stake the long stem if needed.

Planting zone definitions are guides--good ones, but they are not infallible. Any given spot could be a micro-climate that varies from typical zonal characteristics and expectations. Broccoli is pretty hardy but, yes, it is finicky.
Cold tolerance depends on conditioning. If your plants had been in warmer conditions before transplanting and the temp drops well below freezing, it is very likely you would lose them. If you broccoli plants had experienced relatively cold weather, it is likely that they would survive.
Sometimes it is wise to err on the side of caution. You might do well to bring the containers inside, but into a space/area that mimics recent temp and light conditions. That is, don't bring them into the high heat and lamp light of the house. Perhaps a porch?? Or you could cover the plants.
Either way, return them outside or uncover them during the day.
We hope this helps.

It's not just about the weather. Broccoli needs soil with a pH range of 6–7. It is a heavy feeder, so thrives where the soil is rich in aged manure or rich compost—or both. When planted and while growing it can benefit from a general garden fertilizer, such as 10-30-10, with more nitrogen after harvesting. And, if you are not practicing appropriate crop rotation, it may fail to thrive because of whatever grew in the spot before. For specific assistance, contact your local extension service. We hope this helps.

It's hard to know exactly what went wrong with your broccoli crop, but consider this:
• Did you amend the soil to the appropriate pH: 6.0-6.5?
• Did you apply potassium and nitrogen before planting and then again to seven weeks after the transplants (or seedings) got established?
• Did you keep the plants well watered and free from stress—such as diseases, weeds, and insects?
• Did you plant too early in spring? The larger that plants are when exposed to a late-season cold period, the higher is the likelihood that they will bolt.
• Did the plants experience a prolonged cold spell, followed by a favorable temps, then high temps? This sounds normal, but the variability may be the cause of bolting.
There is no easy answer. Consider these risks and try again this year. OH, then there's this—if you see broccoli thriving in a garden in your area, tell your tale and ask the gardener what his/her secret is. The best advice is sometimes right next door. Good luck! Let us know how it goes.

You can leave your plants in the ground and keep harvesting the side shoots in the winter months. In the spring you need to plant new broccoli plants to get new buds and florets.

Please see our fall planting chart here and look for your frost dates. It lists broccoli and more! http://www.almanac.com/content...

Broccoli seedlings will take 8 to 12 weeks from transplant until harvest time, depending on the variety. But look for the cues mentioned above! You really only have 1 week or so to do the first harvest. If you leave it too late, yellow flowers will form.