The judging of dahlias is not and cannot be an exact science and so, as a decision must often rest on the Judge’s personal knowledge and experience, they must take care that in arriving at their decision they are not swayed by their personal dislikes or preferences, whether for cultivars, colours, formation or for any other reason.

It is the duty of all who judge dahlias to acquire a thorough knowledge of all the various Classes, their habits of growth, and the formation of their blooms.

All judges must deal fairly and impartially with any infringement of the rules, the show regulations, and all schedule and local requirements of the organisation whose competitive classes are being judged.

The judges should LOOK for perfection in each bloom, but NOT HANDLE THE BLOOM and when assessing its true merits, the quality, i.e. formation, centre, freshness colour and stem, should be regarded as factors of paramount importance; and then, all imperfections, defects and blemishes, termed faults should be considered as items detracting from the merits of the exhibit.

A fault may be minor or serious, in accordance with the circumstances, or the extent, to which it is present in the exhibit and few hard and fast rules can be laid down to deal with each of them. All faults should therefore be carefully assessed and placed within a true perspective in relation to the exhibit as a whole. Please see section on FAULTS.

All dahlias exhibited in competitive classes must conform to the classes in which they are shown, by Classification, Formation or Size.

An unclassified cultivar which conforms with the formation and size, relative to the class in which it is exhibited, and shall be judged on the same basis as a classified cultivar.

An unclassified cultivar which fails to conform to the correct FORMATION of the class in which it is exhibited shall not be disqualified.

The sizes shown in the internationally recognised Class Classification, Formation and Sizes are an indication for garden purposes of the size of blooms obtainable from dahlias grown under reasonably good conditions, and dahlia cultivars are classified accordingly.

Well cultivated plants grown for exhibition, with superior culture or grown in more favourable soil or climatic conditions, may produce larger or smaller blooms and it is not intended that cultivation for exhibition purposes should be discouraged or that larger or smaller blooms be penalised solely because of their size, but it is considered essential, to ensure fair competition and standardisation that size limits be set for each class of dahlia.

Exhibition standards have, therefore, been adopted and blooms exceeding the maximum sizes for the class in which they are exhibited must be disqualified. This applies equally to classified and unclassified cultivars.

Any vases must be disqualified for any of the following reasons:

1. Bloom size incorrect:-

i. Blooms of Large-flowered dahlias exceeding 260mm

ii. Blooms of Medium-flowered dahlias exceeding 220mm

iii. Blooms of Small-flowered dahlias exceeding 170mm

iv. Blooms of Miniature-flowered dahlias exceeding 115mm

v. Blooms of Pompon dahlias exceeding 52mm and Large Pom exceeding 83mm

The florets of blooms exhibited must pass cleanly through, without touching the inside circumference of the ring.

If a vase(s) in a multi-vase exhibit should be N.A.S. for oversize bloom or blooms, then the remainder of the exhibit must be judged and evaluated as a competitive exhibit. The whole exhibit can be considered for awards, and awards to individual vases can be permitted, (except the disqualified vase or vases).  (e.g. Best vase in its class in that exhibit).

2. Blooms artificially supported above the top level of the vase. It should be noted that an artificial support warranting disqualification could be an internal or external support, supporting a weak stem. Pieces of material normally used for packing purposes and not deemed to be supporting stems/& flowers found above the level of the vase, e.g. oasis, pieces of stalk, and paper shall not be a reason for disqualification. Note: If an exhibitor has used internal artificial support above the top level of the vase and it is confirmed, the matter shall be dealt with by the Affiliated Society Committee responsible for the show.

3. Incorrect number of blooms in an exhibit.

4. Classified bloom exhibited in the wrong class.

5. If a vase in a multi-vase exhibit should be N.A.S. for any reason other than oversize bloom(s), then the whole exhibit must be disqualified. The whole exhibit CANNOT be considered for an award, but awards to individual vases, other than the disqualified vase(s), are permitted (e.g. Best vase in its class in that exhibit).

6. All exhibitors are reminded that all buds, whether embryo or showing colour, will be treated as blooms and will result in disqualification under rule 3 if not removed.

7. Where called for in the class for distinct varieties they should be clearly distinct as viewed on the bench.

The blooms should be fresh and clean; all florets should be intact, firm and without blemish or defect. The colour or colours should be clear and well defined.

Generally a Fimbriated dahlia should be a fully double bloom.

1. As a general principle anything that detracts from the perfection of a bloom, or an exhibit, is a "fault" and the seriousness or otherwise of the fault depends upon the degree of imperfection. Whereas a damaged, eaten, or malformed floret at the rear of the bloom does little to detract from its beauty and overall perfection, that same defect on the face of the bloom, one which mars its beauty, would be considered a very serious fault. In judging an exhibit the following faults must be evaluated accordingly.

2. It is a VERY SERIOUS fault if a bloom:

1. Is malformed
2. Faces downwards (less than 45 degrees).

c. Has been badly damaged, eaten, bruised or otherwise blemished on the face of the bloom

d. Has limp drooping florets

e. Has had an excessive number of florets removed

f. Has an open (daisy-eyed) centre (double-flowered cultivars only)

g. Has a centre that is hard and green, large and undeveloped or badly distorted.

h. Has oval or isolated centres.

i. Has a gap created by a missing outer floret.

j. Seriously departs from the standard formation of the class of dahlia for which the class calls.

3. Faults of a LESSER DEGREE, in accordance with the amount by which the fault detracts from the perfection of a bloom, are as follows:

a. Irregular or oval outline of bloom.

b. Has sunken centres.

c. Uneven, irregular, or unbalanced formation.

d. Florets lacking freshness or which are bleached, discoloured, faded, eaten, bruised, malformed or otherwise blemished on the rear of the bloom.

e. Florets that have been removed.

f. Stems which are bent, weak, short jointed, thick and out of proportion.

g. Uneven or inconsistent colouring, but this does not apply to bi-coloured or variegated blooms.

h. Shallow blooms, i.e. those lacking depth or fullness.

i. Blooms which are either immature or past their best.

j. Blooms below the minimum classification size for that classification.

k. Presence of pests.

a. Blooms of pompon dahlias should face upwards on a straight firm stem and any variation of this must be regarded as a fault.

When several blooms are shown together in an exhibit, it is a fault for them to face at different angles.